Remove combined reports option after moving it.

Adds option to choose to use device or host files. The combined reports
functionality has been moved to code_coverage generation in the
tools/build repo.

Won't land until after verifying the bot script is working as expected
in:
https://chromium-review.googlesource.com/c/chromium/tools/build/+/2348094

Bug: 1107004
Change-Id: I628217c9249a0d69c3ec7d82c63aefd59087d6ad
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2353367Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Yuke Liao <liaoyuke@chromium.org>
Commit-Queue: benjamin joyce <bjoyce@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797825}

build/android/PRESUBMIT.py

@@ -73,7 +73,6 @@ def CommonChecks(input_api, output_api):
           output_api,
           unit_tests=[
               J('.', 'emma_coverage_stats_test.py'),
-              J('.', 'generate_jacoco_report_test.py'),
               J('.', 'list_class_verification_failures_test.py'),
               J('gyp', 'util', 'build_utils_test.py'),
               J('gyp', 'util', 'manifest_utils_test.py'),