Add flutter 3+ support. Update dependencies. Fix code style and format issues.

android/app/build.gradle

@@ -26,7 +26,7 @@ apply plugin: 'kotlin-android'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 android {
-    compileSdkVersion 31
+    compileSdkVersion 33
 
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
@@ -36,7 +36,7 @@ android {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "org.thingsboard.app"
         minSdkVersion 21
-        targetSdkVersion 31
+        targetSdkVersion 33
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
     }

android/app/src/main/AndroidManifest.xml

@@ -62,5 +62,15 @@
         />
         <meta-data android:name="io.flutter.network-policy"
                    android:resource="@xml/network_security_config"/>
+
+        <provider
+                android:name="androidx.core.content.FileProvider"
+                android:authorities="${applicationId}.flutter_inappwebview.fileprovider"
+                android:exported="false"
+                android:grantUriPermissions="true">
+            <meta-data
+                    android:name="android.support.FILE_PROVIDER_PATHS"
+                    android:resource="@xml/provider_paths" />
+        </provider>
     </application>
 </manifest>

android/app/src/main/res/xml/provider_paths.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths xmlns:android="http://schemas.android.com/apk/res/android">
+    <external-path
+            name="external_files"
+            path="." />
+</paths>