Set Trichrome min SDK properly

Make the minimum SDK version for all components of Trichrome be Q, if
we're building with the Q SDK.

SDK28 builds of Trichrome are only for temporary testing and can be left
alone until they're removed.

Bug: 952383
Change-Id: I8e9bac555456868ccf414a56f499d03fd2d1ef34
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1566372
Auto-Submit: Richard Coles <torne@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652207}

chrome/android/trichrome.gni

@@ -28,7 +28,8 @@ declare_args() {
 }
 
 trichrome_jinja_variables = [
-  "min_sdk_version=28",
+  # TODO(torne): make minsdk=Q once we no longer build hacky P version
+  "min_sdk_version=$android_sdk_version",
   "target_sdk_version=$android_sdk_version",
   "trichrome_library=$trichrome_library_package",
   "trichrome_version=$trichrome_version_code",