Fixed delay time overflow issue

If locale tracker keeps failing to get the cell info
(e.g. in no coverage area), and the fail count exceeds
a certain number (approximately 8 hours), the exponentionaly
grown retry delay time will overflow. Then the retry delay
time will be incorrectly calculated as the minimum retry
time, which is 2 seconds. This can cause significant
power consumption issue.

Fixed it by limiting the maximum fail count to 30.

Test: manual + unit test
Bug: 116514046
Change-Id: I6e35e983165a23eff3169c5e234ef9bdebb65c68