Revert changes in build.gradle (Bad merge from PR)

Author: Gp2mv3

android/build.gradle

@@ -22,12 +22,12 @@ def DEFAULT_SUPPORT_LIB_VERSION = "23.1.1"
 def DEFAULT_GOOGLE_PLAY_SERVICES_VERSION = "+"
 
 android {
-    compileSdkVersion 26
-    buildToolsVersion "26.0.3"
+    compileSdkVersion project.hasProperty('compileSdkVersion') ? project.compileSdkVersion : DEFAULT_COMPILE_SDK_VERSION
+    buildToolsVersion project.hasProperty('buildToolsVersion') ? project.buildToolsVersion : DEFAULT_BUILD_TOOLS_VERSION
 
     defaultConfig {
         minSdkVersion 16
-        targetSdkVersion 26
+        targetSdkVersion project.hasProperty('targetSdkVersion') ? project.targetSdkVersion : DEFAULT_TARGET_SDK_VERSION
         versionCode 1
         versionName "1.0"
         ndk {
@@ -48,7 +48,7 @@ dependencies {
 
     compile fileTree(dir: 'libs', include: ['*.jar'])
     testCompile 'junit:junit:4.12'
-    compile 'com.android.support:appcompat-v7:26.0.+'
+    compile "com.android.support:appcompat-v7:$supportLibVersion"
     compile 'com.facebook.react:react-native:+'
     compile "com.google.android.gms:play-services-gcm:$googlePlayServicesVersion"
     compile 'me.leolin:ShortcutBadger:1.1.8@aar'