Add hidden API for raw route mask to support call audio routing

refactor.

Bug: b/306395598
Test: Unit test from telecom stack
Change-Id: Ie49456a07b16e5614456f4483ef8072aa7eb8545

telecomm/java/android/telecom/CallAudioState.java

@@ -198,6 +198,16 @@ public final class CallAudioState implements Parcelable {
         }
     }
 
+    /**
+     * @return Bit mask of all routes supported by this call, won't be changed by streaming state.
+     *
+     * @hide
+     */
+    @CallAudioRoute
+    public int getRawSupportedRouteMask() {
+        return supportedRouteMask;
+    }
+
     /**
      * @return The {@link BluetoothDevice} through which audio is being routed.
      *         Will not be {@code null} if {@link #getRoute()} returns {@link #ROUTE_BLUETOOTH}.