Android support topbar title font scaling

[mika-lindell]

• Android only
• To enable font scaling that can be adjusted via Android Settings-app:
  • Accessibility -> Display size and text -> Font size
• Adds options.topBar.title.allowFontScaling
• Adds and updated unit tests
• When allowFontScaling is enabled, sets top bar title to use SP units. When font scaling is 1.0, it should be the same size as when using DIP
• Here it's set to false by default, because it can conflict with other top bar options like subtitle, height, fontSize etc. that existing users may have
• I'm thinking about making similar changes to iOS, but I wanted feedback on this one first. iOS has some issues especially when "Larger accessibility sizes"-setting is enabled

{
   topBar: {
      title: {
         text: "My title",
         fontSize: 18,
         allowFontScaling: true,
      },
   },
}

allowFontScaling=false	allowFontScaling=true

Allowing font scaling in top bar title seems to be convention in "standard" Android apps:

Settings that can change font scaling in users' device

[mika-lindell]

textSizeUnit is not available before api level 30

[mika-lindell]

For it to make sense from the perspective of options, I didn't find a way to set units without setting font size. Using titleTextView.textSize returns scaled font size, so need to have the absolute font size somewhere