Mark updatable APEXes

Mark updatable APEXes as updatable: true so that they are opted-out from
optimizations that make sense only for non-updatable modules; such as
symlinking to the libs in the system partition.

Bug: 149805758
Test: m and check that there is no symlink from the APEX to the system
partition.

Exempt-From-Owner-Approval: cherry-pick from internal

Merged-In: I8029f3e4d84d76c8937f38fa3053556f7184652f
(cherry picked from commit 684fa779)
Change-Id: I8029f3e4d84d76c8937f38fa3053556f7184652f