Add agent for printing breakpoints

This can be used to test performance of breakpointed code in a
lightweight way or to ensure that code is reaching expected locations.

See tools/breakpoint-logger/README.md for information on how to use.

Also added the ability to pass explicit agents for run-test to load
before running tests.

Test: ./test/run-test                                                 \
        --host                                                        \
        --dev                                                         \
        --with-agent                                                  \
        'libbreakpointlogger.so=LMain;->main([Ljava/lang/String;)V@0' \
        001-HelloWorld

Bug: 68259370

Change-Id: I409c940a34b1e823ec50649cdb3c51e5a81a09ab