Add a flag to protect overwrite app optimization mode to restricted mode.

- Skip set app optimization mode to restricted if the flag disabled.

Bug: 348192536
Fix: 348192536
Test: atest
Flag: EXEMPT bug fix
Change-Id: I92d320ce1edfe9b7044afdcd058651b0d54bd6bd

tests/robotests/src/com/android/settings/fuelgauge/PowerUsageFeatureProviderImplTest.java

@@ -77,6 +77,11 @@ public class PowerUsageFeatureProviderImplTest {
         assertThat(mPowerFeatureProvider.isBatteryTipsEnabled()).isFalse();
     }
 
+    @Test
+    public void isRestrictedModeOverwriteEnabled_returnFalse() {
+        assertThat(mPowerFeatureProvider.isRestrictedModeOverwriteEnabled()).isFalse();
+    }
+
     @Test
     public void isForceExpireAppOptimizationModeEnabled_returnFalse() {
         assertThat(mPowerFeatureProvider.isForceExpireAppOptimizationModeEnabled()).isFalse();