Remove unnecessary versions from multidex's build.gradle.

frameworks/multidex/library does not stand alone as a gradle project
and should always be inheriting these values from the parent build.

Change-Id: I10eb64f2ad38d0bf278d5300e26a637c481b9b00
diff --git a/library/build.gradle b/library/build.gradle
index 40c626b..0fe5882 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -1,9 +1,6 @@
 apply plugin: 'android-library'
 
 android {
-    compileSdkVersion 19
-    buildToolsVersion = '19.0.3'
-
     sourceSets {
         main {
             java.srcDirs         = ['src']