[Material] Material theme builder (#313)

* Initial version.

* Applied theming.

* Updated UI

- Updated ThemeData to baseline values

* Update readme

Update readme

* Update readme

* Update readme

* [INDEX] Adding a listing for this.

* [Material Theme Builder] PR feedback and updating for new text theme API.

* [Material Theme Builder] More PR feedback.

* [Material Theme Builder] Adding to Travis.

* [Material Theme Builder] Rebase conflicts.

* [Theme Generator] Adding 1 link to the readme.

Co-authored-by: yasmineevjen <yasmineevjen@users.noreply.github.com>

material_theme_builder/android/app/build.gradle

@@ -0,0 +1,67 @@
+def localProperties = new Properties()
+def localPropertiesFile = rootProject.file('local.properties')
+if (localPropertiesFile.exists()) {
+    localPropertiesFile.withReader('UTF-8') { reader ->
+        localProperties.load(reader)
+    }
+}
+
+def flutterRoot = localProperties.getProperty('flutter.sdk')
+if (flutterRoot == null) {
+    throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
+}
+
+def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
+if (flutterVersionCode == null) {
+    flutterVersionCode = '1'
+}
+
+def flutterVersionName = localProperties.getProperty('flutter.versionName')
+if (flutterVersionName == null) {
+    flutterVersionName = '1.0'
+}
+
+apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
+apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
+
+android {
+    compileSdkVersion 28
+
+    sourceSets {
+        main.java.srcDirs += 'src/main/kotlin'
+    }
+
+    lintOptions {
+        disable 'InvalidPackage'
+    }
+
+    defaultConfig {
+        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
+        applicationId "com.example.material_theme_builder"
+        minSdkVersion 16
+        targetSdkVersion 28
+        versionCode flutterVersionCode.toInteger()
+        versionName flutterVersionName
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+    }
+
+    buildTypes {
+        release {
+            // TODO: Add your own signing config for the release build.
+            // Signing with the debug keys for now, so `flutter run --release` works.
+            signingConfig signingConfigs.debug
+        }
+    }
+}
+
+flutter {
+    source '../..'
+}
+
+dependencies {
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation 'androidx.test:runner:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
+}