Steps to reproduce:
1) Download attached project and open in Unity
2) Make sure that Vulkan is the only Graphics API in the Player Settings
3) Make sure that Format of the texture in the Assets folder is set to RGB(A) Compressed ASTC HDR 6x6 block
4) Build and Run on a device

Expected result: Texture format should fall back. Image should be rendered
Actual result: Image is not rendered, ASTC+HDR texture format is not detected

Devices under testing:
Reproduced with:
VLNQA00302, Samsung Galaxy A70 (SM-A705FN), Android 9, CPU: Snapdragon 675 SM6150, GPU: Adreno (TM) 612

Not reproduced with:
VLNQA00217, Razer Phone 2 (Phone 2), Android 9, CPU: Snapdragon 845 SDM845, GPU: Adreno (TM) 630
VLNQA00149, Samsung Galaxy S9 (SM-G960F), Android 9, CPU: Exynos 9 Series 9810, GPU: Mali-G72
VLNQA00220, Samsung Galaxy Note9 (SM-N960F), Android 8.1.0, CPU: Exynos 9 Series 9810, GPU: Mali-G72

Reproduced with:
2019.3.0b9, 2002.1.0a12

Note: Using Gles2 ASTC+HDR texture is decompressed but fails to render the image and warning in the logcat is printed:
WARNING: RGBA Compressed ASTC6X6 UFloat format is not supported, decompressing texture (expected)
Unsupported GraphicsFormat(0) for SetPixel operations.

Note: Using Gles3 Graphics API works fine, warning in the logcat (expected) and image is rendered:
WARNING: RGBA Compressed ASTC6X6 UFloat format is not supported, decompressing texture