Improved logging of APN context

Instead of sharing one local log for all APN context, create
one local log for each APN context.

Bug: 130819450
Test: Manual

Merged-In: Ie5c42cf7b52f0bb81b28d9f2e865728245892300
Change-Id: Ie5c42cf7b52f0bb81b28d9f2e865728245892300
(cherry picked from commit 504350c5)