This commit updates the docs examples to Angular v12.1.3. In addition to
updating the dependencies versions, it also updates the projects'
structure and configs to more closely match what a new v12 CLI app would
look like. See, also, the [diff][1] between a basic v11.2.11 CLI app and
a v12.1.3 one.
[1]: https://github.com/cexbrayat/angular-cli-diff/compare/11.2.11..12.1.3
PR Close#42949
This commit disables the Selenium Promise Manager when running e2e tests
for docs examples in order to more closely align them with new apps
created with CLI v11. This change requires that any async operations in
tests are handled explicitly (e.g. using `async/await` or
`Promise#then()`).
PR Close#39818
