hercules: Remove BT tether overlay

Change-Id: I7063554747dc000def642d3f7c1614352eb6ede9
hercules: consolidate overlays into celox-common

  * move common overlays from skyrocket/hercules into celox

Change-Id: I848cd330f03a91da411e7170f9b96817a13b39a7
Merge remote-tracking branch 'cm/cm-10.2' into HEAD