Fix Calculator locale change log spam

Bug: 33075625

I was checking for string reference equality when I should have been
checking for equals(). This may not have mattered before the libcore
changes in N.

Avoid this issue by directly comparing locales instead of strings.

Minor comment and log cleanups in the same area.

Change-Id: If96b5636dad92c2dfccacedd9c387f4ca0398ca0