To reproduce:
1. Open attached project;
2. Switch to Android Platform;
3. Build and run the "11_LightingScenarioTest" scene to Android devices;
4. When app launches, press "Enable/disable Draw Instanced" a few times and examine the spotlight.

Expected result: spotlight intensity when Terrain Instancing is enabled is the same as when Terrain Instancing is disabled.
Actual result: when Terrain Instancing is enabled, Spotlight intensity is extremely lower.

Reproduced with:
Version 2018.2.0a6 (6822e3ba621c)
Tue, 24 Apr 2018 23:10:10 GMT
Branch: graphics/terrain/gpu/staging/r8g8/remove-r16

Devices Under Testing:
Reproduced with:
-Razer Phone
GPU: Adreno (TM) 540
CPU: Snapdragon 835 (MSM8998)
OS: 7.1.1
-Xiaomi MI 5
GPU: Adreno (TM) 530
CPU: Snapdragon 820 (MSM8996)
OS: 7.0
-Xiaomi Mi Max
GPU: Adreno (TM) 510
CPU: Snapdragon 650 (MSM8956)
OS: 7.0
-Samsung SM G930F
GPU: Mali-T880
CPU: Exynos 8 Octa (8890)
OS: 7.0
-Samsung SM G950F
GPU: Mali-G71
CPU: Exynos 9 Octa (8895)
OS: 8.0
-Samsung SM N950U1
GPU: Adreno (TM) 540
CPU: Snapdragon 835 (MSM8998)
OS: 7.1.1
-Samsung SM G928F
GPU: Mali-T760
CPU: Exynos 7 Octa (7420)
OS: 7.0
-Google Pixel 2XL
GPU: Adreno (TM) 540
CPU: Snapdragon 835 (MSM8998)
OS: 8.0
-Google Nexus 5
GPU: Adreno (TM) 330
CPU: Snapdragon 800 (MSM8974)
OS: 6.0.1