Fix DeviceAtomTestCase#getUid()

Current implementation assumes there is only one line in
`cmd package list packages` output. That assumption is not correct.

This change parses all lines of the output and looks for the target
package info in all lines of the output.

Bug: 231638833
Test: atest android.cts.statsd.validation.ValidationTests\#testPartialWakelock
Test: Manually test multiple line output from `cmd package list
packages`

Ignore-AOSP-First: Fix needed in T branch; will be cherry-picked to AOSP
as well.

Change-Id: I36f602509a48d39f6d1946dbb306498b89d42aa4
1 file changed