Remove "preparing StaticLib" messages
Remove "preparing StaticLib" messages

The preparing StaticLib messages don't provide any useful information,
remove them to clean up build output.

Bug: 24409581
Change-Id: I81fa7c47fd0d10846a21667b6421b4777260d0e9

xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build