Update app/build.gradle to support older android version

Author: chengxuanying

app/build.gradle

@@ -5,11 +5,11 @@ apply plugin: 'kotlin-android'
 apply plugin: 'kotlin-android-extensions'
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 26
     defaultConfig {
         applicationId "com.nanchen.screenrecorder"
         minSdkVersion 14
-        targetSdkVersion 28
+        targetSdkVersion 22
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -25,7 +25,7 @@ android {
 dependencies {
     implementation fileTree(include: ['*.jar'], dir: 'libs')
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-    implementation 'com.android.support:appcompat-v7:28.0.0'
+    implementation 'com.android.support:appcompat-v7:26.0.0'
     implementation 'com.android.support.constraint:constraint-layout:1.1.3'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'