gradle: use compileClasspath instead of compileOnly

In the previous commit 46ddf071b ("gradle: add Android jar to
smack-android-extensions compile classpath") we already added the
Android jar using compileClasspath to smack-android-extensions. Now
use the same configuration for smack-android, since compileOnly is
deprecated.

smack-android/build.gradle

@@ -24,5 +24,5 @@ dependencies {
 	}
 
 	// Add the Android jar to the Eclipse .classpath.
-	compileOnly files(androidBootClasspath)
+	compileClasspath files(androidBootClasspath)
 }