overlay: set mobile network MTU back to 1500

This fixes tethering.

Change-Id: Ia0fd510f5574b17127ace5daa8333b5b95289b64
Recovery: update for TWRP 2.8

Relocate files for new recovery inclusion methods

Change-Id: Ib6d89832ae954e9405e8c68a88882a84b56916d3