Do not use CLusterManager when not needed

[radzio]

 Caused by: java.lang.ClassNotFoundException: Didn't find class "com.google.maps.android.clustering.ClusterManager" on path: DexPathList[[zip file "/data/app/net.droidlabs.ticketsreminder.debug-38aeX_U6xg0I3aCGunMJ0g==/base.apk", zip file "/data/app/net.droidlabs.ticketsreminder.debug-38aeX_U6xg0I3aCGunMJ0g==/split_lib_directories_apk.apk"],nativeLibraryDirectories=[/data/app/net.droidlabs.ticketsreminder.debug-38aeX_U6xg0I3aCGunMJ0g==/lib/x86, /data/app/net.droidlabs.ticketsreminder.debug-38aeX_U6xg0I3aCGunMJ0g==/base.apk!/lib/x86, /data/app/net.droidlabs.ticketsreminder.debug-38aeX_U6xg0I3aCGunMJ0g==/split_lib_directories_apk.apk!/lib/x86, /system/lib, /system/vendor/lib]]
                                                                                       at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:93)
                                                                                       at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
                                                                                       at java.lang.ClassLoader.loadClass