Amend the test following console output changes. (#22093)

This is the follow-up to https://github.com/flutter/flutter/pull/20958.

dev/devicelab/bin/tasks/run_release_test.dart

@@ -52,24 +52,24 @@ void main() {
       await run.exitCode;
       if (stderr.isNotEmpty)
         throw 'flutter run --release had output on standard error.';
-      if (stdout.first == 'Building flutter tool...')
+      if (stdout.first.startsWith('Building flutter tool...'))
         stdout.removeAt(0);
-      if (stdout.first == 'Running "flutter packages get" in ui...')
+      if (stdout.first.startsWith('Running "flutter packages get" in ui...'))
         stdout.removeAt(0);
-      if (stdout.first == 'Initializing gradle...')
+      if (stdout.first.startsWith('Initializing gradle...'))
         stdout.removeAt(0);
-      if (stdout.first == 'Resolving dependencies...')
+      if (stdout.first.startsWith('Resolving dependencies...'))
         stdout.removeAt(0);
       if (!(stdout.first.startsWith('Launching lib/main.dart on ') && stdout.first.endsWith(' in release mode...')))
         throw 'flutter run --release had unexpected first line: ${stdout.first}';
       stdout.removeAt(0);
-      if (stdout.first != 'Running \'gradlew assembleRelease\'...')
+      if (!stdout.first.startsWith('Running \'gradlew assembleRelease\'...'))
         throw 'flutter run --release had unexpected second line: ${stdout.first}';
       stdout.removeAt(0);
       if (!(stdout.first.startsWith('Built build/app/outputs/apk/release/app-release.apk (') && stdout.first.endsWith('MB).')))
         throw 'flutter run --release had unexpected third line: ${stdout.first}';
       stdout.removeAt(0);
-      if (stdout.first == 'Installing build/app/outputs/apk/app.apk...')
+      if (stdout.first.startsWith('Installing build/app/outputs/apk/app.apk...'))
         stdout.removeAt(0);
       if (stdout.join('\n') != '\nTo quit, press "q".\n\nApplication finished.') {
         throw 'flutter run --release had unexpected output after third line:\n'