Switch to 3 framebuffer surface buffers

Switches from 2 to 3 buffers for SurfaceFlinger's FramebufferSurface.
This avoids an issue exposed by the HWC2 path where, since we now defer
buffer release, the GL driver ends up hanging on dequeueBuffer, which
is called in response to a glViewport command.

Bug: 62783122
Test: android.server.cts.ActivityManagerDisplayLockedKeyguardTests#
          testVirtualDisplayHidesContentWhenLocked

Change-Id: I6f68823c652fcfb12b16154653154ffe54457209
1 file changed