Fix the selection of locale from SIM mcc.

Two issues - getting config then setting locale by mcc and then setting the config (to set
mcc/mnc) would overwrite the locale set in the middle.  Also, using a "new Configuration()"
instead of asking the ActivityManager.getConfiguration gets different values than the current
ones, and would also overwrite our change.

bug: 2241461
bug: 2239810