Add tests for AppOpsService foreground location

Test transition between different proc states and
verify that the location perm is granted in the
right states.

Bug: 130313658
Test: atest FrameworksServicesTests:AppOpsServiceTest
Change-Id: I8f9789e1699a776a30b2580a606266ec4b72b2d8
diff --git a/services/core/java/com/android/server/appop/AppOpsService.java b/services/core/java/com/android/server/appop/AppOpsService.java
index 4c3bb8c..873cadb 100644
--- a/services/core/java/com/android/server/appop/AppOpsService.java
+++ b/services/core/java/com/android/server/appop/AppOpsService.java
@@ -220,7 +220,8 @@
      * global Settings. Any access to this class or its fields should be done while
      * holding the AppOpsService lock.
      */
-    private final class Constants extends ContentObserver {
+    @VisibleForTesting
+    final class Constants extends ContentObserver {
         // Key names stored in the settings value.
         private static final String KEY_TOP_STATE_SETTLE_TIME = "top_state_settle_time";
         private static final String KEY_FG_SERVICE_STATE_SETTLE_TIME
@@ -305,7 +306,8 @@
         }
     }
 
-    private final Constants mConstants;
+    @VisibleForTesting
+    final Constants mConstants;
 
     @VisibleForTesting
     static final class UidState {