Cht-core: Add person icon is not monochrome

[abbyad]

Describe the bug
The white monochrome icon for new person has a pink head.

To Reproduce
Steps to reproduce the behavior:

1. Go to People tab
2. Click on a place
3. In RHS see the add person icon in the FAB has a head the same color as the People tab.

Expected behavior
The icons used in the FAB are meant to be monochrome white.

Screenshots

Environment

• Instance: gamma.dev running 3.6, cht.app running 3.4.0
• Browser: Chrome 75 on Windows 10, and also seen on Mac
• Version: tested on versions 3.4.0 and 3.6.0

[garethbowen]

Ready for AT on 5877-fill-icon-head

[newtewt]

Looks good on mobile and web versions.

[jacqedwards]

Super excited that our person icon will have a head that matches their body! :)