Flesh PackageInstaller benchmarks out

Add benchmarks to measure the duration between session committing
and receiving the callback. This patch creates the following
benchmarks.
* a single apk session
* three single apk sessions
* a multiple packages session
* three multiple packages sessions
* a multiple apks session

Test: TID="PackageManagerPerfTests" ; \
    atest \
    ${TID}:android.content.pm.PackageInstallerBenchmark

Bug: 194755410
Change-Id: I80a9fab1574b04f97bb91fb31f9fc508c1f47f9d