A lot of problems with lights and materials in OpenGL ES

Examples "materals" and "lights" are not displayed correctly on Android 4.4.4 (OpenGL ES 3.0).
In original entities are too dark to be distinguished:

("materals" example - show just black screen)

1. First of all - changing intensity of lights is not affect on anything in any following scenarios.
By the way, that's why I have different level of entities brightness on desktop and android I wrote about in interest mailing list: http://lists.qt-project.org/pipermail/interest/2016-June/022994.html,
and why I have to increase ambient component of DiffuseMapMaterial in android version.

2. There something wrong with NormalDiffuseMapMaterial and NormalDiffuseSpecularMapMaterial. If I set maximum ambient to PlaneEntity in "lights" example (or PlaneEntity in "materals") in efforts to make it lighter and distinguished, I got white plane:

3. When I change those materials to DiffuseMapMaterial (with maximum ambient) and run apps - I got almost black screen (just a few silhouette of entities), until I remove SpotLight from the scene.
And only on this moment PlaneEntity "appears":

Then, one needs to set maximum ambient to other materials one by one. And for now make them DiffuseMapMaterial, because as I mentioned before NormalDiffuseMapMaterial and NormalDiffuseSpecularMapMaterial - will get pure white result - see barrel on the screenshot):

In other hand, on desktop everything looks perfect (where OpenGL 3.1 shaders are used).

I use latest qt 3d 5.7 (c3fdb888fbd94de0f6b7b1a6859cba8132ecc93d) with those 4 not yet merged commits (to be able to run applications on android)

1. https://codereview.qt-project.org/#/c/164993/2
2. https://codereview.qt-project.org/#/c/164994/2
3. https://codereview.qt-project.org/#/c/164995/2
4. https://codereview.qt-project.org/#/c/164996/