Don't drop shell permissions before running test.

Fix: 182612502
Fix: 182610293
Test: atest PlatformCompatGating:com.android.tests.gating.PlatformCompatGatingTest -- --abi x86_64
Change-Id: Ie4fe44c5b79cb4dc50d8e8c7a5303f116670e333

tests/PlatformCompatGating/test-rules/src/android/compat/testing/PlatformCompatChangeRule.java

@@ -100,7 +100,6 @@ public class PlatformCompatChangeRule extends CoreCompatChangeRule {
                 platformCompat.setOverridesForTest(new CompatibilityChangeConfig(mConfig),
                         packageName);
                 try {
-                    uiAutomation.dropShellPermissionIdentity();
                     mTestStatement.evaluate();
                 } finally {
                     adoptShellPermissions(uiAutomation);