Persistent storage in Carrier Config debug shell commands

Add support for Persistent storage in Carrier Config shell debug
commands. Adds an option "-p" in the command "cc set-config" to control
that the new value should be stored persistent.

The syntax for "cc set-value" then becomes:
cc set-value [-s SLOT_ID] [-p] KEY [NEW_VALUE]

Bug: 144544956
Test: atest TeleServiceTests
Change-Id: I775503c32974d658dace68ea88cdbeb564ca7c19
2 files changed