How to reproduce:
1. Open the attached lwrp_render_texture.zip' project
2. Build & Run 'SampleScene' Scene for Android
3. Observe the Scene (checked Toggle enables 'Opaque Texture' parameter)

Expected result: Render Texture has a transparent background
Actual result: Render Texture has a black background

Reproducible: 2018.4.4f1(4.10.0), 2019.1.11f1(5.16.1), 2019.2.0b10(6.9.0), 2019.3.0a10(6.5.3)
Can't reproduce:
- 2017.4, because the package manager was not introduced
- 2019.3.0a10 (6.9.0), because of "'VFXManager' is inaccessible due to its protection level" error (case 1167156)

Repro Devices:

2018.4.4f1:
VLNQA00016, Samsung Galaxy S4 Mini (GT-I9195), Android 4.4.2, CPU: Snapdragon S4 Plus MSM8960, GPU: Adreno (TM) 305 (GLES2)

2019.1.11f1, 2019.2.0b10:
VLNQA00138, Huawei P20 Pro (CLT-L29), Android 8.1.0, CPU: HiSilicon Kirin 970, GPU: Mali-G72 (Vulkan, GLES3)
VLNQA00009, Samsung Galaxy Note8 (SM-N950F), Android 9, CPU: Exynos 9 Octa 8895, GPU: Mali-G71 (Vulkan, GLES3)
VLNQA00119, Xiaomi Mi 5 (MI 5), Android 7.0, CPU: Snapdragon 820 MSM8996, GPU: Adreno (TM) 530 (GLES3)
VLNQA00016, Samsung Galaxy S4 Mini (GT-I9195), Android 4.4.2, CPU: Snapdragon S4 Plus MSM8960, GPU: Adreno (TM) 305 (GLES2)
VLNQA00233, Meizu - (PRO 6 Plus), Android 7.0.0, CPU: Exynos 8 Octa 8890, GPU: Mali-T880 (GLES3, Vulkan)
VLNQA00266, Xiaomi Mi A2 (Mi A2), Android 9, CPU: Snapdragon 660, GPU: Adreno (TM) 512 (GLES3)
VLNQA00150, Samsung Galaxy S9 (SM-G960U), Android 9, CPU: Snapdragon 845 SDM845, GPU: Adreno (TM) 630 (GLES3)
VLNQA00232 iPhones 8 Plus (iOS 12.1.2)
VLNQA00239 iPad Mini 2 (iOS 10.3.1)

2019.3.0a10 (all API):
VLNQA00016, Samsung Galaxy S4 Mini (GT-I9195), Android 4.4.2, CPU: Snapdragon S4 Plus MSM8960, GPU: Adreno (TM) 305
VLNQA00255, Samsung Galaxy Note3 Neo (SM-N7505), Android 4.4.2, CPU: Exynos 5 Hexa 5260, GPU: Mali-T624
VLNQA00119, Xiaomi Mi 5 (MI 5), Android 7.0, CPU: Snapdragon 820 MSM8996, GPU: Adreno (TM) 530
VLNQA00233, Meizu - (PRO 6 Plus), Android 7.0.0, CPU: Exynos 8 Octa 8890, GPU: Mali-T880
VLNQA00266, Xiaomi Mi A2 (Mi A2), Android 9, CPU: Snapdragon 660, GPU: Adreno (TM) 512
VLNQA00150, Samsung Galaxy S9 (SM-G960U), Android 9, CPU: Snapdragon 845 SDM845, GPU: Adreno (TM) 630
VLNQA00138, Huawei P20 Pro (CLT-L29), Android 8.1.0, CPU: HiSilicon Kirin 970, GPU: Mali-G72
VLNQA00009, Samsung Galaxy Note8 (SM-N950F), Android 9, CPU: Exynos 9 Octa 8895, GPU: Mali-G71cmd
VLNQA00239 iPad Mini 2 (iOS 10.3.1)
VLNQA00239 iPad Mini 2 (iOS 10.3.1)

No Repro Devices:
VLNQA00255, Samsung Galaxy Note3 Neo (SM-N7505), Android 4.4.2, CPU: Exynos 5 Hexa 5260, GPU: Mali-T624
VLNQA00020, Samsung Galaxy S3 (SGH-T999), Android 4.3, CPU: Snapdragon S4 Plus MSM8960, GPU: Adreno (TM) 225

Can't reproduce:
VLNQA00035, Motorola DROID MAXX 2 (XT1021), Android 4.4.4, CPU: NOT FOUND, GPU: Adreno (TM) 305, because of [INSTALL_FAILED_OLDER_SDK] error
VLNQA00043, Samsung Galaxy S3 Mini Value Edition (GT-I8200N), Android 4.2.2, CPU: Marvell PXA988, GPU: GC1000 Graphics Engine, because of [INSTALL_FAILED_OLDER_SDK] error

Notes:
- Not reproducible in Editor, Standalone
- Same results with Mono and IL2CPP Scripting Backend