modules/display-caf: [TEMP HACK] remove -Werror in common_flags

It floats into other parts of the build and causes breakage.
(see: hardware/qcom/audio-caf/libalsa-intf signedness errors)

Needs a real fix later.

Change-Id: If23c07ac0db42d36ad86d66ea4aaea5e6db57684
Remove obsolete hwui property

Change-Id: Ie7f71c64050f1ad6ad10f3def75325a719259cdb
Merge remote-tracking branch 'upstream/cm-10.2' into cm-10.2