feat: add Amazon Fire TV platform support

[subhanahmed047]

The isBrowserSupported function in the utils/player.js fails if the Safari Version is < 13. However, this check doesn't work for Amazon Fire TV devices. Even tho they have a Version/4.0 in the user agent string, the browser still supports all other requirements to support playback with Shaka Player.

Here are a couple of examples of the different FireTV device user agents:

Fire TV Stick 4K - 1st Gen:

'Mozilla/5.0 (Linux; Android 7.1.2; AFTMM Build/NS6289; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/100.0.4896.127 Mobile Safari/537.36'

Fire TV Stick - 3rd Gen:

'Mozilla/5.0 (Linux; Android 9; AFTSSS Build/PS7285.2877N; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/96.0.4664.92 Mobile Safari/537.36'

The fix involves identifying the Amazon Fire TV device based on the parameters described in the Amazon Fire TV docs and disabling the Safari version check for these devices.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to
  not work as expected)
• This change requires a documentation update

Checklist:

• I have signed the Google CLA https://cla.developers.google.com/
• My code follows the style guidelines of this project
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have verified my change on multiple browsers on different platforms (Amazon FireTV Stick 4k, and non-4k device)
• I have run ./build/all.py and the build passes
• I have run ./build/test.py and all tests pass (while most tests pass, some tests around TextDisplayer are failing even on the main branch for Edge and Firefox, even tho those tests seem irrelevant to the changes in this PR). I'll create an issue around that.

[joeyparrish]

Renamed to "feat:" since this is adding functionality. Will review shortly.