Make UiccController's local log bigger on debuggable builds.

Also make the variable private and expose a single static method to add
a new line to it for uniformity, and start logging UiccController as a
prefix.

Bug: 132080087
Test: make, look at UiccController dump
Change-Id: Iacb47ea1a0571926a8a90c2eb36a37eae3dd6dc2