Add flag for controling app image generation

So that package manager service can control this.

Bug: 72696798
Test: manual

(cherry picked from commit ad45a1b89bc3b6ec84ac32c4200be3d3c1d056fa)

Merged-In: I15fa74aff24ef14d22541117408840f80b7d300f
Change-Id: If8886187a67f392dd83061b9f44fae8d3bac22be
5 files changed