Propagate flutter tool verbose flag through gradle to flutter build bundle. (#18246)

packages/flutter_tools/gradle/flutter.gradle

@@ -256,6 +256,10 @@ class FlutterPlugin implements Plugin<Project> {
             target = project.property('target')
         }
 
+        Boolean verboseValue = null
+        if (project.hasProperty('verbose')) {
+            verboseValue = project.property('verbose').toBoolean()
+        }
         Boolean previewDart2Value = true
         if (project.hasProperty('preview-dart-2')) {
             previewDart2Value = project.property('preview-dart-2').toBoolean()
@@ -310,6 +314,7 @@ class FlutterPlugin implements Plugin<Project> {
                 localEngine this.localEngine
                 localEngineSrcPath this.localEngineSrcPath
                 targetPath target
+                verbose verboseValue
                 previewDart2 previewDart2Value
                 fileSystemRoots fileSystemRootsValue
                 fileSystemScheme fileSystemSchemeValue
@@ -353,6 +358,8 @@ abstract class BaseFlutterTask extends DefaultTask {
     @Input
     String targetPath
     @Optional @Input
+    Boolean verbose
+    @Optional @Input
     Boolean previewDart2
     @Optional @Input
     String[] fileSystemRoots
@@ -442,6 +449,9 @@ abstract class BaseFlutterTask extends DefaultTask {
             args "build", "bundle"
             args "--suppress-analytics"
             args "--target", targetPath
+            if (verbose) {
+                args "--verbose"
+            }
             if (previewDart2) {
                 args "--preview-dart-2"
             } else {

packages/flutter_tools/lib/src/android/gradle.dart

@@ -314,7 +314,9 @@ Future<Null> _buildGradleProjectV2(String gradle, BuildInfo buildInfo, String ta
   final Status status = logger.startProgress('Running \'gradlew $assembleTask\'...', expectSlowOperation: true);
   final String gradlePath = fs.file(gradle).absolute.path;
   final List<String> command = <String>[gradlePath];
-  if (!logger.isVerbose) {
+  if (logger.isVerbose) {
+    command.add('-Pverbose=true');
+  } else {
     command.add('-q');
   }
   if (artifacts is LocalEngineArtifacts) {