Don't set CCACHE_BASEDIR if its already set

 * enable use of shared ccache

Change-Id: Ic708a5d5169291d674b167aa2c87bf2c8adaafae
ota: Include copies of the recovery scripts even if shipping in block mode
ota: Fix recovery-script cleanups in block mode

Change-Id: Iadb480f8062cfb7a0e6c9024e32ac0d71a7481d7