Assumptions:
1. The input report file can be a zip file result from a standard cts
test tool, or a test_result.xml
2. If there are multiple cts reports after the -r flag, it means to view
these files as one report. The script aggregates them according to the
same rules as b/293809772.
Bug: 296323842
Test: ./compare_cts_reports.py -r [a.zip, test_result_1.xml] -r [b.zip,
test_result_2.xml] -m [1, 2] [-d output_directory] [-o]
Change-Id: I885dd07cd40d38ba0c2ee1cb38570a926606a4d9
9ea1b08298