Add support for reading `net/data/ssl/certificates` files

* After supporting netty, the certificates files are needed to start up the HTTP server. Those files must be moved to the emulator which happens through the changes in AndroidTest.xml, isolated-storage
has been disabled to allow the emulator to access the storage freely without restriction. Otherwise
I will have to change the destination of the data files which will result in divergence.

* Added the newly introduced test utility java classes including netty to the `jarjar_excludes` as they must not be jarjared because they are not part of the bootclasspath.

Test: atest NetHttpTests
Bug: 319629150
Bug: 304217500
Change-Id: I2331873a9e178783319f889a377ba7e390ecdd6f
diff --git a/Cronet/tests/mts/AndroidTest.xml b/Cronet/tests/mts/AndroidTest.xml
index 3470531..5a4fed6 100644
--- a/Cronet/tests/mts/AndroidTest.xml
+++ b/Cronet/tests/mts/AndroidTest.xml
@@ -24,6 +24,10 @@
         <option name="test-file-name" value="NetHttpTests.apk" />
     </target_preparer>
 
+    <target_preparer class="com.android.tradefed.targetprep.PushFilePreparer">
+        <option name="push-file" key="net" value="/storage/emulated/0/chromium_tests_root/net" />
+    </target_preparer>
+
     <option name="test-tag" value="NetHttpTests" />
     <test class="com.android.tradefed.testtype.AndroidJUnitTest" >
         <option name="package" value="android.net.http.mts" />
@@ -43,10 +47,11 @@
         <!-- b/316559294 -->
         <option name="exclude-filter" value="org.chromium.net.NQETest#testQuicDisabled" />
         <!-- b/316554711-->
-        <option name="exclude-filter" value="org.chromium.net.NetworkChangesTest" /> 
+        <option name="exclude-filter" value="org.chromium.net.NetworkChangesTest" />
         <!-- b/316550794 -->
         <option name="exclude-filter" value="org.chromium.net.impl.CronetLoggerTest#testEngineCreation" />
         <option name="hidden-api-checks" value="false"/>
+        <option name="isolated-storage" value="false"/>
     </test>
 
     <!-- Only run NetHttpTests in MTS if the Tethering Mainline module is installed. -->