Fixed that locale tracker incorrectly used the invalid cell info

Fixed that the locale tracker used the invalid cached cell info
when airplane mode is turned on. We should clear the cache when
airplane mode is on.

The previous fix ag/4058309 was reverted because it caused crash.
This is the right fix with unit tests added.

Test: Manual
Bug: 79230575, 79861643, 79771106
Merged-In: I410c309a6afa42d98299819675afa8c3de151215
Change-Id: I410c309a6afa42d98299819675afa8c3de151215
(cherry picked from commit 5d391ebcec77aebd99e772bcfeaec1ecd8d5b469)
2 files changed