Upgrade to latest Flutter version (fix Gradle and other errors)

android/build.gradle

@@ -9,12 +9,12 @@ allprojects {
     }
 }
 
-rootProject.buildDir = '../build'
+rootProject.buildDir = "../build"
 subprojects {
     project.buildDir = "${rootProject.buildDir}/${project.name}"
 }
 subprojects {
-    project.evaluationDependsOn(':app')
+    project.evaluationDependsOn(":app")
 }
 
 tasks.register("clean", Delete) {