Have Android bin/run_ wrappers call test_env.py directly.

Currently, when a bot runs a test (say, url_unittests) on an
Android build, it'll launch `python test_env.py logdog_wrapper.py
bin/run_url_unittests` (roughly speaking).

This CL flips that around so that the generated bin/run_url_unittests
script will invoke test_env.py to launch url_unittests (and the bot
will then invoke bin/run_url_unittests directly).

This slightly reduces the discrepancy between what a dev runs locally
and what the bot runs, and will make Android consistent with every other
platform.

Bug: 816629
Change-Id: I76727641b5a4362f37762ed4ed4b175eea58ce2e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2506634Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Dirk Pranke <dpranke@google.com>
Cr-Commit-Position: refs/heads/master@{#822042}

build/config/android/internal_rules.gni

@@ -739,10 +739,12 @@ template("test_runner_script") {
       data_deps = []
     }
 
+    executable = "//testing/test_env.py"
+
     if (defined(android_test_runner_script)) {
-      executable = android_test_runner_script
+      _runner_script = android_test_runner_script
     } else {
-      executable = "//build/android/test_runner.py"
+      _runner_script = "//build/android/test_runner.py"
     }
 
     deps = []
@@ -753,9 +755,10 @@ template("test_runner_script") {
     if (defined(invoker.data_deps)) {
       data_deps = invoker.data_deps
     }
-    data = []
+    data = [ "//testing/test_env.py" ]
 
     executable_args = [
+      "@WrappedPath(" + rebase_path(_runner_script, root_build_dir) + ")",
       _test_type,
       "--output-directory",
       "@WrappedPath(.)",

tools/mb/mb.py

@@ -1532,7 +1532,6 @@ class MetaBuildWrapper(object):
       if asan:
         cmdline += [os.path.join('bin', 'run_with_asan'), '--']
       cmdline += [
-          '../../testing/test_env.py',
           '../../build/android/test_wrapper/logdog_wrapper.py',
           '--target', target,
           '--logdog-bin-cmd', '../../.task_template_packages/logdog_butler',