Log APK hash for package install attempts in the Event Log.

This CL adds a package_digest field to the install_package_attempt
event. The field is populated with the SHA-256 digest of the contents
of the APK iff the user has consented to app verification and app
verification is enabled.

Bug: 11275004
Bug: 10605940

(cherry picked from commit 8fca480bee00578c1529b1f32ab30af096db82dd)

Change-Id: I9773925f7e397ada26efac022349dc8e4af01208
Import translations. DO NOT MERGE

Change-Id: I304ee40cd39348cc847e6fd69a50300e612dfa51
Auto-generated-cl: translation import
Import translations. DO NOT MERGE

Change-Id: I020d2c5e2c66ea260e6c6ee665425124c3d579b0
Auto-generated-cl: translation import
Merge branch 'android-4.4.1_r1' into HEAD