Update to build.gradle for 4.5.0 release

Author: joeygrover

sdl_android/build.gradle

@@ -2,12 +2,12 @@ apply plugin: 'com.android.library'
 
 android {
     compileSdkVersion 26
-    buildToolsVersion "25.0.2"
+    buildToolsVersion "25.0.3"
     defaultConfig {
         minSdkVersion 8
         targetSdkVersion 19
         versionCode 3
-        versionName "RC2-4.5.0"
+        versionName "4.5.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
         resValue "string", "SDL_LIB_VERSION", '\"' + versionName + '\"'
     }