Have isValidPhoneId and isValidSlotIndex based on activeModemCount.

Bug: 142514392
Test: sanity and unittest
Merged-In: Ia66ee24151d1ec8ecde2dcb4c824a19b4d2cd172
Change-Id: Ia66ee24151d1ec8ecde2dcb4c824a19b4d2cd172
(cherry picked from commit dde04f8f4afe453dd844a8b012320b7757cdf67c)
1 file changed