Help on issue #128350014: runInstallCreate from pm command asks...

...to run as user -1 but is calling from user 0

Improve the message to give the full uid of the caller to help identify
where such problems are coming from:

Bug: 128350014
Test: manual
Change-Id: Ibb88224e706f6d5c0d5bb495239d4abcfe24f671