Fix: Set default color in all activity indicators

[ashwinibm]

Apply default color for other ActivityIndicators

Reference:
#275
https://github.com/Instawork/instawork/pull/13363/files#r667629321

[adamstep]

This is Instawork's default color. It shouldn't be hard-coded in HV.

[adamstep]

Can we use the default color per-platform? Is that what the RN spinner does by default?

[flochtililoch]

The version of RN we're using has a bug that prevents Android from using the default color on spinners. We've already taken the step to hardcode our color in #275, but that might not be the most elegant solution. Maybe we can undo #275 and instead write a patch for our RN app, so that default color is not ignored on Android.

[adamstep]

I'm ok hard-coding the defaults in HV. But ideally we can work around the RN bug by hard-coding the original default color.

[ashwinibm]

Closing in favor of using a patch in the client app instead https://github.com/Instawork/mobile/pull/3848