To reproduce:
1. Create a new project with LW VR template
2. In the package manager, add PostProcessing
3. Change building settings to Android
4. Add the shaders from the User attached folder "Post Shaders"
5. Choose any of them and compile
5. Notice the errors in the inspector window

Actual result: all the shaders including cginc throws error
Expected result: There should not be any errors

Reproduced with:2017.4.12f1; 2018.1.9f2; 2018.2.10f1; 2018.3.0b4; 2019.1.0a2

Errors:

failed to open source file: 'Common.cginc'
Compiling Vertex program
Platform defines: UNITY_ENABLE_REFLECTION_BUFFERS UNITY_USE_DITHER_MASK_FOR_ALPHABLENDED_SHADOWS UNITY_PBS_USE_BRDF1 UNITY_SPECCUBE_BOX_PROJECTION UNITY_SPECCUBE_BLENDING UNITY_ENABLE_DETAIL_NORMALMAP SHADER_API_DESKTOP UNITY_COLORSPACE_GAMMA UNITY_LIGHT_PROBE_PROXY_VOLUME UNITY_LIGHTMAP_FULL_HDR

Shader error in 'Hidden/Post FX/Ambient Occlusion': failed to open source file: 'Common.cginc' at Assets/AmbientOcclusion.cginc(8) (on d3d11)
Compiling Vertex program
Platform defines: UNITY_ENABLE_REFLECTION_BUFFERS UNITY_USE_DITHER_MASK_FOR_ALPHABLENDED_SHADOWS UNITY_PBS_USE_BRDF1 UNITY_SPECCUBE_BOX_PROJECTION UNITY_SPECCUBE_BLENDING UNITY_ENABLE_DETAIL_NORMALMAP SHADER_API_DESKTOP UNITY_COLORSPACE_GAMMA UNITY_LIGHT_PROBE_PROXY_VOLUME UNITY_LIGHTMAP_FULL_HDR

failed to open source file: 'Common.cginc'
Compiling Vertex program with STEREO_MULTIVIEW_ON
Platform defines: UNITY_NO_DXT5nm UNITY_ENABLE_REFLECTION_BUFFERS UNITY_NO_CUBEMAP_ARRAY UNITY_USE_DITHER_MASK_FOR_ALPHABLENDED_SHADOWS UNITY_PBS_USE_BRDF1 UNITY_SPECCUBE_BOX_PROJECTION UNITY_SPECCUBE_BLENDING UNITY_ENABLE_DETAIL_NORMALMAP SHADER_API_DESKTOP UNITY_LIGHTMAP_DLDR_ENCODING