diff --git a/compatibility_matrices/compatibility_matrix.4.xml b/compatibility_matrices/compatibility_matrix.4.xml
index bb7637a..952f53d 100644
--- a/compatibility_matrices/compatibility_matrix.4.xml
+++ b/compatibility_matrices/compatibility_matrix.4.xml
@@ -1,5 +1,5 @@
 <compatibility-matrix version="1.0" type="framework" level="4">
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.atrace</name>
         <version>1.0</version>
         <interface>
@@ -7,7 +7,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.audio</name>
         <version>5.0</version>
         <interface>
@@ -15,7 +15,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.audio.effect</name>
         <version>5.0</version>
         <interface>
@@ -23,7 +23,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.authsecret</name>
         <version>1.0</version>
         <interface>
@@ -31,7 +31,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.automotive.audiocontrol</name>
         <version>1.0</version>
         <interface>
@@ -39,7 +39,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.automotive.evs</name>
         <version>1.0</version>
         <interface>
@@ -47,7 +47,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.automotive.vehicle</name>
         <version>2.0</version>
         <interface>
@@ -55,7 +55,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.biometrics.face</name>
         <version>1.0</version>
         <interface>
@@ -63,7 +63,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.biometrics.fingerprint</name>
         <version>2.1</version>
         <interface>
@@ -71,7 +71,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.bluetooth</name>
         <version>1.0</version>
         <interface>
@@ -79,7 +79,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.bluetooth.audio</name>
         <version>2.0</version>
         <interface>
@@ -87,7 +87,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.boot</name>
         <version>1.0</version>
         <interface>
@@ -95,7 +95,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.broadcastradio</name>
         <version>1.0-1</version>
         <interface>
@@ -103,7 +103,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.broadcastradio</name>
         <version>2.0</version>
         <interface>
@@ -111,7 +111,7 @@
             <regex-instance>.*</regex-instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.camera.provider</name>
         <version>2.4-5</version>
         <interface>
@@ -119,7 +119,7 @@
             <regex-instance>[^/]+/[0-9]+</regex-instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.cas</name>
         <version>1.1</version>
         <interface>
@@ -127,7 +127,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.configstore</name>
         <version>1.1</version>
         <interface>
@@ -135,7 +135,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.confirmationui</name>
         <version>1.0</version>
         <interface>
@@ -143,7 +143,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.contexthub</name>
         <version>1.0</version>
         <interface>
@@ -151,7 +151,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.drm</name>
         <version>1.0-2</version>
         <interface>
@@ -163,7 +163,7 @@
             <regex-instance>.*</regex-instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.dumpstate</name>
         <version>1.0</version>
         <interface>
@@ -171,7 +171,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.gatekeeper</name>
         <version>1.0</version>
         <interface>
@@ -179,7 +179,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.gnss</name>
         <version>2.0</version>
         <interface>
@@ -190,7 +190,7 @@
     <!-- Either the AIDL or the HIDL allocator HAL must exist on the device.
          If the HIDL composer HAL exists, it must be at least version 2.0.
          See DeviceManifestTest.GrallocHal -->
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.graphics.allocator</name>
         <version>2.0</version>
         <version>3.0</version>
@@ -199,7 +199,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.graphics.composer</name>
         <version>2.1-3</version>
         <interface>
@@ -207,7 +207,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.graphics.mapper</name>
         <version>2.1</version>
         <version>3.0</version>
@@ -219,7 +219,7 @@
     <!-- Either the AIDL or the HIDL health HAL must exist on the device.
          If the HIDL health HAL exists, it must be at least version 2.0.
          See DeviceManifestTest.HealthHal -->
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.health</name>
         <version>2.0</version>
         <interface>
@@ -227,7 +227,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.health.storage</name>
         <version>1.0</version>
         <interface>
@@ -235,7 +235,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.ir</name>
         <version>1.0</version>
         <interface>
@@ -243,7 +243,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.input.classifier</name>
         <version>1.0</version>
         <interface>
@@ -251,7 +251,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.keymaster</name>
         <version>3.0</version>
         <version>4.0</version>
@@ -260,7 +260,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.keymaster</name>
         <version>4.0</version>
         <interface>
@@ -268,7 +268,7 @@
             <instance>strongbox</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.light</name>
         <version>2.0</version>
         <interface>
@@ -276,7 +276,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.media.c2</name>
         <version>1.0</version>
         <interface>
@@ -291,7 +291,7 @@
             <instance>software</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.media.omx</name>
         <version>1.0</version>
         <interface>
@@ -303,7 +303,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.memtrack</name>
         <version>1.0</version>
         <interface>
@@ -311,7 +311,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.neuralnetworks</name>
         <version>1.0-2</version>
         <interface>
@@ -319,7 +319,7 @@
             <regex-instance>.*</regex-instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.nfc</name>
         <version>1.2</version>
         <interface>
@@ -327,7 +327,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.oemlock</name>
         <version>1.0</version>
         <interface>
@@ -335,7 +335,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.power</name>
         <version>1.0-3</version>
         <interface>
@@ -343,7 +343,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.power.stats</name>
         <version>1.0</version>
         <interface>
@@ -351,7 +351,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.radio</name>
         <version>1.4</version>
         <interface>
@@ -361,7 +361,7 @@
             <instance>slot3</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.radio</name>
         <version>1.2</version>
         <interface>
@@ -370,7 +370,7 @@
             <instance>slot2</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.radio.config</name>
         <!--
         Note: Devices launching with target-level 4, if implementing the
@@ -384,7 +384,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.renderscript</name>
         <version>1.0</version>
         <interface>
@@ -392,7 +392,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.secure_element</name>
         <version>1.0</version>
         <interface>
@@ -401,7 +401,7 @@
             <regex-instance>SIM[1-9][0-9]*</regex-instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.sensors</name>
         <version>1.0</version>
         <version>2.0</version>
@@ -410,7 +410,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.soundtrigger</name>
         <version>2.0-2</version>
         <interface>
@@ -418,7 +418,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.tetheroffload.config</name>
         <version>1.0</version>
         <interface>
@@ -426,7 +426,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.tetheroffload.control</name>
         <version>1.0</version>
         <interface>
@@ -434,7 +434,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.thermal</name>
         <version>2.0</version>
         <interface>
@@ -442,7 +442,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.tv.cec</name>
         <version>1.0</version>
         <interface>
@@ -450,7 +450,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.tv.input</name>
         <version>1.0</version>
         <interface>
@@ -458,7 +458,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.usb</name>
         <version>1.0-2</version>
         <interface>
@@ -466,7 +466,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.usb.gadget</name>
         <version>1.0</version>
         <interface>
@@ -474,7 +474,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.vibrator</name>
         <version>1.0-3</version>
         <interface>
@@ -482,7 +482,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.vr</name>
         <version>1.0</version>
         <interface>
@@ -490,7 +490,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.weaver</name>
         <version>1.0</version>
         <interface>
@@ -498,7 +498,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.wifi</name>
         <version>1.0-3</version>
         <interface>
@@ -506,7 +506,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.wifi.hostapd</name>
         <version>1.0-1</version>
         <interface>
@@ -514,7 +514,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="true">
+    <hal format="hidl">
         <name>android.hardware.wifi.supplicant</name>
         <version>1.0-2</version>
         <interface>