Reverted back decision to also build samples on Android platform.

Although samples should also work for Android platform, currently there is no available mechanism to package each sample app into individual *.apk.

Source/CMakeLists.txt

@@ -96,8 +96,10 @@ add_subdirectory (Engine)
 # Urho3D tool targets
 add_subdirectory (Tools)
 
-# Urho3D samples (should work also on iOS and Android)
-if (ENABLE_SAMPLES)
+# Urho3D samples
+# Samples are built on iOS platform too when enabled
+# Although samples should also work for Android platform, currently there is no available mechanism to package each sample apps into individual *.apk
+if (NOT ANDROID AND ENABLE_SAMPLES)
     add_subdirectory (Samples)
 endif ()