Add API EuiccController#startOtaUpdatingIfNecessary

This function requests calling app has WRITE_EMBEDDED_SUBSCRIPTIONS
permission. It will check whether the OTA update needed to be done
first. If current eUICC OS isn't latest one and OTA needed to be
performed, it will update eUICC OS. When the OS update is started or
finished, a broadcast will be sent.

Bug: 37279356
Test: Included
Merged-In: I68f88dd01f23259859f6069046a96fa23b880c24
Change-Id: I68f88dd01f23259859f6069046a96fa23b880c24