Release 8.0.0

[langsmith]

Part of the 8.0.0 release of the Maps SDK for Android

CHANGELOG

Noteworthy changes:

• Bumped Maps SDK version to 8.0.0 (Maps SDK v8.0.0 #1061)
• Adding example of onStyleImageMissing listener usage (Adding example of onStyleImageMissing listener usage #1070)
• Adding ignore sign in button (Adding ignore sign in button #1033)
• Adding example of ignorePlacement/allowOverlap for text and icons (Adding example of ignorePlacement/allowOverlap for text and icons #1063)
• New basic SymbolLayer icon examples (Refactoring and splitting basic SymbolLayer icon examples #1030)
• Adding example of using TurfTransformation#circle to create visual ring (Adding example of using TurfTransformation#circle to create visual ring  #1039)
• Adding multiple color formatting to TextFieldMultipleFormatsActivity (Adding multiple color formatting to TextFieldMultipleFormatsActivity #1054)

Release checklist

• Cut the release branch
• Update CHANGELOG.md on the release branch
• Update whatsnew file on the release branch
• Merge the release branch into master
• Tag 8.0.0 in https://github.com/mapbox/mapbox-android-demo/releases