Reproduction steps:
1. Open the attached user's project "Android Transparency Shader Test 2.zip"
2. Go to the Graphics Settings and disable 'Use HDR' for all Graphics Tiers
3. Build for Android and notice the blur and color invert shaders using GrabPasses
4. Enable 'Use HDR' in the Graphics settings for all Graphics tiers
5. Build for Android and notice the blur and color invert shaders no longer working

Expected result: GrabPass shaders work on Android when 'Use HDR' is enabled on OpenGLES 3
Actual result: GrabPass shaders are not working on Android when 'Use HDR' is enabled on OpenGLES 3 (see attached Results.png)

Reproduces on: 2019.4.29f1, 2020.3.14f1, 2021.1.14f1, 2021.2.0b1, 2022.1.0a1

Reproducible with these devices (OpenGLES 3):
N/A, Samsung Galaxy S9 (SM-G960F), Android 8.0.0, CPU: Exynos 9 Series 9810, GPU: Mali-G72
VLNQA00318, Oneplus 7Pro (GM1913), Android 10, CPU: Snapdragon 855 SM8150, GPU: Adreno (TM) 640
VLNQA00231, Huawei HUAWEI Mate 20 Pro (LYA-L29), Android 9, CPU: HiSilicon Kirin 980, GPU: Mali-G76
VLNQA00024, Xiaomi Mi 5 (MI 5), Android 7.0, CPU: Snapdragon 820 MSM8996, GPU: Adreno (TM) 530

Not reproducible with these devices (Vulkan):
N/A, Samsung Galaxy S9 (SM-G960F), Android 8.0.0, CPU: Exynos 9 Series 9810, GPU: Mali-G72
VLNQA00318, Oneplus 7Pro (GM1913), Android 10, CPU: Snapdragon 855 SM8150, GPU: Adreno (TM) 640
VLNQA00231, Huawei HUAWEI Mate 20 Pro (LYA-L29), Android 9, CPU: HiSilicon Kirin 980, GPU: Mali-G76
iPad Pro 12.9 1st gen (iOS 13.4.1)