add license and update grade

android/app/build.gradle

@@ -4,11 +4,11 @@ configurations.all {
     resolutionStrategy.force 'com.android.support:support-annotations:27.1.1'
 }
 android {
-    compileSdkVersion 26
+    compileSdkVersion 30
     defaultConfig {
         applicationId "me.yoqi.app.lizihelper"
-        minSdkVersion 15
-        targetSdkVersion 26
+        minSdkVersion 16
+        targetSdkVersion 30
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

android/build.gradle

@@ -7,7 +7,8 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.0.0'
+        classpath "com.android.tools.build:gradle:4.1.0"
+
         
 
         // NOTE: Do not place your application dependencies here; they belong

android/gradle/wrapper/gradle-wrapper.properties

@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.5-bin.zip