Reverts: flutter/flutter#150733
Initiated by: gmackall
Reason for reverting: This breaks apps that use plugins that use `compileSdk` 31, some of which we use in our postsubmit (so it blocks the tree).
Original PR Author: gmackall
Reviewed By: {jason-simmons}
This change reverts the following previous change:
Manual engine roll to https://github.com/flutter/engine/pull/53532, because the roll requires lockfile generation.
Manual recreation of https://github.com/flutter/flutter/pull/148911
Entire PR is just the output of
```
flutter update-packages --force-upgrade
```
followed by (run from the root of the flutter repo)
```
find . -type d -name 'android' | dart dev/tools/bin/generate_gradle_lockfiles.dart --no-gradle-generation --no-exclusion
```
This PR increases Android's `minSdkVersion` to 21.
There are two changes in this PR aside from simply increasing the number
from 19 to 21 everywhere.
First, tests using `flutter_gallery` fail without updating the
lockfiles. The changes in the PR are the results of running
`dev/tools/bin/generate_gradle_lockfiles.dart` on that app.
Second, from
[here](https://developer.android.com/build/multidex#mdex-pre-l):
> if your minSdkVersion is 21 or higher, multidex is enabled by default
and you don't need the multidex library.
As a result, the `multidex` option everywhere is obsolete. This PR
removes all logic and tests related to that option that I could find.
`Google testing` and `customer_tests` pass on this PR, so it seems like
this won't be too breaking if it is at all. If needed I'll give this
some time to bake in the framework before landing the flutter/engine
PRs.
Context: https://github.com/flutter/flutter/issues/138117,
https://github.com/flutter/flutter/issues/141277, b/319373605
* Revert "Mark last failing test after gradle update as flaky. (#91423)"
This reverts commit 46a52d03bddc74a78135d39ef2084503cc2156d7.
* Revert "fix android template for Gradle 7 (#91411)"
This reverts commit 51d06d537fe37dd8f42002346d8545a489aed427.
* Revert "Add explicit version for mac and windows openjdk. (#91408)"
This reverts commit bf429f2771f486602579bd5ff85ee2cfbb0794af.
* Revert "Update the openjdk version used by linux android tests. (#91405)"
This reverts commit 2144ab8b45b8da12a94838b092c8ebc62085457f.
* Revert "Migrate to Gradle 7.0.2 / AGP 7.0.1 (#90642)"
This reverts commit b6459f9b633279f84a92eabc6bc5f82304fc1eae.
