libbluetooth_log: Always output the source file and line

The logger functions provided by liblog do not systematically
output the source file and line in the log line.
To ensure consistent log output the file is directly included
in the log message.

Bug: 328213986
Flag: EXEMPT, log change
Test: atest libbluetooth_log_test
Change-Id: I874b6aca24f47192afa48a968252400dc5c05bc6