Revert "Increase polling frequency again temporarily to fix A/V issues"

This reverts commit 8d16bbc5a354d302abfd912b8d88d9c7feb3948f.

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

Change-Id: I40f354af2e0ec21ce60708de90513b73ba4a0412
Revert "Enable silence detection and don't driver the audio encoder"

This reverts commit cf2604f8940093e249ed7e5382c12ba544a48545.

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

Change-Id: I7ec792ae4d49e4c4a85399c29a58111f7b2cc112