RxJS 7 versions prior to 7.4.0 export ES5 code, whereas Angular
applications using RxJS 6 today use ES2015. This was fixed in RxJS 7.4.0
which exposes ES2015 entrypoints as well. This commit updates Angular's
peer dependencies to require the newer RxJS.
PR Close#43748
We can't update the framework to rxjs7 until version 13, because it contains breaking changes, but we can allow users to opt into it since all of our code should be compatible.
These changes expand the allowed version range of rxjs and add an integration test to verify that we don't get compilation errors. Note that we also have a test that runs the AIO examples against rxjs 7 already (#42660).
Fixes#41897.
PR Close#42991