Add OverlayManagerService#setEnableExclusive

This lets settings use one call to set the current theme overlay
for the "android" package.

Test: Change theme in Settings -> Display
Change-Id: Ia566e58c5479dedb7184f4218151f8080f8ebc0f
diff --git a/services/core/java/com/android/server/om/OverlayManagerService.java b/services/core/java/com/android/server/om/OverlayManagerService.java
index 1af541d..2026c1b 100644
--- a/services/core/java/com/android/server/om/OverlayManagerService.java
+++ b/services/core/java/com/android/server/om/OverlayManagerService.java
@@ -504,6 +504,25 @@
         }
 
         @Override
+        public boolean setEnabledExclusive(@Nullable final String packageName, final boolean enable,
+                int userId) throws RemoteException {
+            enforceChangeOverlayPackagesPermission("setEnabled");
+            userId = handleIncomingUser(userId, "setEnabled");
+            if (packageName == null) {
+                return false;
+            }
+
+            final long ident = Binder.clearCallingIdentity();
+            try {
+                synchronized (mLock) {
+                    return mImpl.setEnabledExclusive(packageName, enable, userId);
+                }
+            } finally {
+                Binder.restoreCallingIdentity(ident);
+            }
+        }
+
+        @Override
         public boolean setPriority(@Nullable final String packageName,
                 @Nullable final String parentPackageName, int userId) throws RemoteException {
             enforceChangeOverlayPackagesPermission("setPriority");