libgui: New mutex for ConsumerBase frame callbacks

Adds a new mutex to protect ConsumerBase's mFrameAvailableListener
separately from the main mMutex. This prevents deadlocks when trying
to perform callbacks in response to other calls that come through
ConsumerBase.

Bug: 62915791
Test: EncodeVirtualDisplayWithCompositionTest#
          testRenderingMaxResolutionRemotely

Change-Id: I244dc2d83488e452d9690c0d7847c9ff15a95dbb
diff --git a/libs/gui/ConsumerBase.cpp b/libs/gui/ConsumerBase.cpp
index c2b10a9..3d36376 100644
--- a/libs/gui/ConsumerBase.cpp
+++ b/libs/gui/ConsumerBase.cpp
@@ -106,7 +106,7 @@
 
     sp<FrameAvailableListener> listener;
     { // scope for the lock
-        Mutex::Autolock lock(mMutex);
+        Mutex::Autolock lock(mFrameAvailableMutex);
         listener = mFrameAvailableListener.promote();
     }
 
@@ -121,7 +121,7 @@
 
     sp<FrameAvailableListener> listener;
     {
-        Mutex::Autolock lock(mMutex);
+        Mutex::Autolock lock(mFrameAvailableMutex);
         listener = mFrameAvailableListener.promote();
     }
 
@@ -185,7 +185,7 @@
 void ConsumerBase::setFrameAvailableListener(
         const wp<FrameAvailableListener>& listener) {
     CB_LOGV("setFrameAvailableListener");
-    Mutex::Autolock lock(mMutex);
+    Mutex::Autolock lock(mFrameAvailableMutex);
     mFrameAvailableListener = listener;
 }