Handle volume keys to apps in Vr mode

When a device is in Vr mode -
 - Volume key event must be passed to the audio subsystem to reflect
 changes when the configuration is enabled.
 - When the configuration is disabled, neither the apps not the audio
 subsystem should be able to receive the volume key events

Bug: 37625887
Bug: 36280728
Test:
- Verified that the app doesn't receive volume events
- Verified that the system volume bar is also not triggered

Change-Id: I245f7797873f764d0b017879723a6dbff1bb4d36
Signed-off-by: Karthik Ravi Shankar <karthikrs@google.com>

core/res/res/values/config.xml

@@ -2872,4 +2872,8 @@
 
     <!-- Additional non-platform defined secure settings exposed to Instant Apps -->
     <string-array name="config_allowedSecureInstantAppSettings"></string-array>
+
+    <!-- Handle volume keys directly in Window Manager without passing them to the foreground app -->
+    <bool name="config_handleVolumeKeysInWindowManager">false</bool>
+
 </resources>

core/res/res/values/symbols.xml

@@ -3010,4 +3010,5 @@
   <java-symbol type="array" name="config_allowedSystemInstantAppSettings" />
   <java-symbol type="array" name="config_allowedSecureInstantAppSettings" />
 
+  <java-symbol type="bool" name="config_handleVolumeKeysInWindowManager" />
 </resources>

services/core/java/com/android/server/policy/PhoneWindowManager.java

@@ -584,6 +584,8 @@ public class PhoneWindowManager implements WindowManagerPolicy {
     boolean mTranslucentDecorEnabled = true;
     boolean mUseTvRouting;
 
+    private boolean mHandleVolumeKeysInWM;
+
     int mPointerLocationMode = 0; // guarded by mLock
 
     // The last window we were told about in focusChanged.
@@ -1928,6 +1930,9 @@ public class PhoneWindowManager implements WindowManagerPolicy {
 
         mUseTvRouting = AudioSystem.getPlatformType(mContext) == AudioSystem.PLATFORM_TELEVISION;
 
+        mHandleVolumeKeysInWM = mContext.getResources().getBoolean(
+                com.android.internal.R.bool.config_handleVolumeKeysInWindowManager);
+
         readConfigurationDependentBehaviors();
 
         mAccessibilityManager = (AccessibilityManager) context.getSystemService(
@@ -3522,11 +3527,18 @@ public class PhoneWindowManager implements WindowManagerPolicy {
         } else if (keyCode == KeyEvent.KEYCODE_VOLUME_UP
                 || keyCode == KeyEvent.KEYCODE_VOLUME_DOWN
                 || keyCode == KeyEvent.KEYCODE_VOLUME_MUTE) {
-            if (mUseTvRouting) {
-                // On TVs volume keys never go to the foreground app.
+            if (mUseTvRouting || mHandleVolumeKeysInWM) {
+                // On TVs or when the configuration is enabled, volume keys never
+                // go to the foreground app.
                 dispatchDirectAudioEvent(event);
                 return -1;
             }
+
+            // If the device is in Vr mode, drop the volume keys and don't
+            // forward it to the application/dispatch the audio event.
+            if (mPersistentVrModeEnabled) {
+                return -1;
+            }
         } else if (keyCode == KeyEvent.KEYCODE_TAB && event.isMetaPressed()) {
             // Pass through keyboard navigation keys.
             return 0;
@@ -5911,8 +5923,8 @@ public class PhoneWindowManager implements WindowManagerPolicy {
                         }
                     }
                 }
-                if (mUseTvRouting) {
-                    // On TVs, defer special key handlings to
+                if (mUseTvRouting || mHandleVolumeKeysInWM) {
+                    // Defer special key handlings to
                     // {@link interceptKeyBeforeDispatching()}.
                     result |= ACTION_PASS_TO_USER;
                 } else if ((result & ACTION_PASS_TO_USER) == 0) {