add component metadata to all CTS module configs

Bug: 36140955
Bug: 35360169
Test: new unit test to ensure that all modules have this field
Change-Id: Id856f93c0d2a018be65bff33459b4b703d23257d
diff --git a/tests/backup/AndroidTest.xml b/tests/backup/AndroidTest.xml
index 3d96fe2..f292943 100644
--- a/tests/backup/AndroidTest.xml
+++ b/tests/backup/AndroidTest.xml
@@ -15,6 +15,7 @@
   ~ limitations under the License
   -->
 <configuration description="Config for CTS Backup test cases">
+    <option name="config-descriptor:metadata" key="component" value="backup" />
     <target_preparer class="com.android.tradefed.targetprep.suite.SuiteApkInstaller">
         <option name="cleanup-apks" value="true" />
         <option name="test-file-name" value="CtsBackupApp.apk" />