[2D][Sprite Atlas] Normal map renders differently with 2D lights when packed in sprite atlas

Both primary and secondary texture in packed atlas uses the same sRGB setting, resulting in lighting issues of packed normal map when "Color Space" is set to "Linear"

Repro steps:
1. Open SampleScene in attached project
2. Go to Edit > Project Settings > Player, Observe "Color Space" is set to "Linear"
3. Observe lighting of both point lights look the same in gameview
4. Enter playmode
5. Observe lighting of right point light changes in gameview

Expected result: Lighting of normal maps should not change if packed in an atlas
Actual result: Lighting of normal maps change if packed in an atlas