Revert "Better power savings with wifi display code."

This reverts commit 575a5361fc970476cd7979638ee3ac00cc6e5024.
Revert "Increase polling frequency again temporarily to fix A/V issues"

This reverts commit 8d16bbc5a354d302abfd912b8d88d9c7feb3948f.
Revert "Enable silence detection and don't driver the audio encoder"

This reverts commit cf2604f8940093e249ed7e5382c12ba544a48545.

Conflicts:
	media/libstagefright/wifi-display/source/Converter.h

Change-Id: I552e227e322807fbc1fa2caf2cb869e3eb0bb676