HFP: Allow SCO audio to be forcibly connected

* Normally, Android only allows SCO audio to be connected in several
  allowed cases (e.g. in call, in ringing, in virtual call state, etc)
* Sometimes, it is necessary to force a SCO audio connection (e.g.
  during PTS test)
* This change adds setForceScoAudio(boolean) hidden, system only method
  to allow such behaviour

Bug: 38040125
Test: PTS HFP tests
Change-Id: I28f295c98da5bebb837c2a5423c7acde81af73f7
diff --git a/core/java/android/bluetooth/BluetoothHeadset.java b/core/java/android/bluetooth/BluetoothHeadset.java
index 2d25659..c31a9b2 100644
--- a/core/java/android/bluetooth/BluetoothHeadset.java
+++ b/core/java/android/bluetooth/BluetoothHeadset.java
@@ -767,6 +767,28 @@
     }
 
     /**
+     * Force SCO audio to be opened regardless any other restrictions
+     *
+     * @param forced Whether or not SCO audio connection should be forced:
+     *                 True to force SCO audio
+     *                 False to use SCO audio in normal manner
+     * @hide
+     */
+    public void setForceScoAudio(boolean forced) {
+        if (VDBG) log("setForceScoAudio " + String.valueOf(forced));
+        if (mService != null && isEnabled()) {
+            try {
+                mService.setForceScoAudio(forced);
+            } catch (RemoteException e) {
+              Log.e(TAG, e.toString());
+            }
+        } else {
+            Log.w(TAG, "Proxy not attached to service");
+            if (DBG) Log.d(TAG, Log.getStackTraceString(new Throwable()));
+        }
+    }
+
+    /**
      * Check if Bluetooth SCO audio is connected.
      *
      * <p>Requires {@link android.Manifest.permission#BLUETOOTH} permission.
diff --git a/core/java/android/bluetooth/IBluetoothHeadset.aidl b/core/java/android/bluetooth/IBluetoothHeadset.aidl
index 6ad442b..6bd0d7f 100755
--- a/core/java/android/bluetooth/IBluetoothHeadset.aidl
+++ b/core/java/android/bluetooth/IBluetoothHeadset.aidl
@@ -52,6 +52,7 @@
     boolean disconnectAudio();
     void setAudioRouteAllowed(boolean allowed);
     boolean getAudioRouteAllowed();
+    void setForceScoAudio(boolean forced);
     boolean startScoUsingVirtualVoiceCall(in BluetoothDevice device);
     boolean stopScoUsingVirtualVoiceCall(in BluetoothDevice device);
     void phoneStateChanged(int numActive, int numHeld, int callState, String number, int type);