recovery: default recovery updating to false

Default recovery flashing on system updates to false. This can be
overridden for specific builds/devices, but the option can be enabled
or disabled on all builds.

Change-Id: Ia1bc94bd1e5f799fc894286a6b2f4f7a8a3816dd
Merge commit 'e0e8c2772ec580d5a69adf742ede09f438b18399' into cm-11.0