15.0.1 RC 2

[MorrisJobke]

Changelog since 15.0.1 RC 1 (#13346):

• [stable15] Fix apps menu overlapping #13404 Fix apps menu overlapping
• [stable15] Use the real logger in the settings #13405 Use the real logger in the settings
• [stable15] CSP: Allow fonts to be provided in data #13411 CSP: Allow fonts to be provided in data
• [stable15] HttpClient getHeader can return empty string #13425 HttpClient getHeader can return empty string
• [stable15] add support for boolean default #13444 add support for boolean default
• notifications#245 Update richObjectStringParser.js

Pending PRs:

• [stable15] Respect classification of calendar events in activity stream #13439 Respect classification of calendar events in activity stream