Verify package name from carrierConfig for bindService

PACKAGE_OVERRIDE_STRING from carrierConfig is not null
but empty by default. Empty string is used instead of
"com.android.phone" by default. It cause bind error.

Bug: 119584293
Test: Manual

Change-Id: I0156477edf1722c1c4872f3f252a146a84c8e076
Signed-off-by: Sehee Park <sehee32.park@samsung.com>