SurfaceFlinger: override frame rate for applications that use setFrameRate

When possible, override the frame rate of an app if it explicitly
set a preferred frame rate.

Test: atest FrameRateOverrideHostTest
Test: SF unit tests
Bug: 170502573
Change-Id: Ifcb7dd1ad0423b05efe8a0e86f2d988c49e74054
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 95bf510..f990bc7 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -880,7 +880,7 @@
      */
     bool hasInputInfo() const;
 
-    uid_t getOwnerUid() { return mOwnerUid; }
+    virtual uid_t getOwnerUid() const { return mOwnerUid; }
 
     pid_t getOwnerPid() { return mOwnerPid; }