Closes #9433: Update Flank version in ui-tests Dockerfile (#9466)

fix: flank_snapshot requires direct shard value

-1 shards -> 50 shards

fix: adjust flank-x86.yml shard value

try old results generator in flank-x86.yml

fix: legacy-junit-report -> legacy-junit-result

revert to modern reporting

automation/taskcluster/androidTest/flank-x86.yml

@@ -50,7 +50,7 @@ flank:
   project: GOOGLE_PROJECT
   # test shards - the amount of groups to split the test suite into
   # set to -1 to use one shard per test.
-  max-test-shards: -1 
+  max-test-shards: 50 
   # num-test-runs: the amount of times to run the tests.
   # 1 runs the tests once. 10 runs all the tests 10x
   num-test-runs: 1

taskcluster/ci/ui-test/kind.yml

@@ -28,7 +28,7 @@ jobs:
             commands:
                 - [wget, {artifact-reference: '<signing/public/build/x86/geckoNightly/target.apk>'}, '-O', app.apk]
                 - [wget, {artifact-reference: '<signing-android-test/public/build/noarch/geckoNightly/target.apk>'}, '-O', android-test.apk]
-                - [automation/taskcluster/androidTest/ui-test.sh, x86, app.apk, android-test.apk, '-1']
+                - [automation/taskcluster/androidTest/ui-test.sh, x86, app.apk, android-test.apk, '50']
             secrets:
                 - name: project/mobile/fenix/firebase
                   key: firebaseToken

taskcluster/docker/ui-tests/Dockerfile

@@ -10,7 +10,7 @@ USER worker:worker
 
 ENV GOOGLE_SDK_DOWNLOAD ./gcloud.tar.gz
 ENV GOOGLE_SDK_VERSION 233
-ENV FLANK_VERSION v8.0.1 
+ENV FLANK_VERSION flank_snapshot
 
 ENV TEST_TOOLS /builds/worker/test-tools
 ENV PATH ${PATH}:${TEST_TOOLS}:${TEST_TOOLS}/google-cloud-sdk/bin