Remove media.cas requirement.

This is a requirement on android phones and tv but
not on watches. Owner will handle putting that requirement
in place, but removing requirement from this file
specifically only in order to have O-MR1 interfaces
frozen.

Bug: 63603463
Test: m system_compatibility_matrix.xml compatibility_matrix.xml manifest.xml system_manifest.xml -j
Change-Id: Iefdc231c2928dfdb8e04a5de8a08ab9b23bae73d
diff --git a/compatibility_matrix.27.xml b/compatibility_matrix.27.xml
index 22ca426..5c81f26 100644
--- a/compatibility_matrix.27.xml
+++ b/compatibility_matrix.27.xml
@@ -71,7 +71,7 @@
             <instance>legacy/0</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="false">
+    <hal format="hidl" optional="true">
         <name>android.hardware.cas</name>
         <version>1.0</version>
         <interface>
diff --git a/compatibility_matrix.current.xml b/compatibility_matrix.current.xml
index 22ca426..5c81f26 100644
--- a/compatibility_matrix.current.xml
+++ b/compatibility_matrix.current.xml
@@ -71,7 +71,7 @@
             <instance>legacy/0</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="false">
+    <hal format="hidl" optional="true">
         <name>android.hardware.cas</name>
         <version>1.0</version>
         <interface>