Previously, [this test][1] would occasionally fail (e.g. on CI) with
"Template cache was not found in $templateCache". This was due to a
combination of:
1. [That test][2] (which removes the cache) being run right before the
failing test.
2. The async `TestBed.compileComponents()` operation run in the
`beforeEach()` block (which sets the cache) not having completed
before the `it()` block.
This commit fixes the issue by ensuring the cache is always set, before
instantiating `CachedResourceLoader`.
This commit also moves some operations that are only needed in one test
from the `beforeEach()` block to that test's `it()` block.
[1]: 79903b1842/packages/platform-browser-dynamic/test/resource_loader/resource_loader_cache_spec.ts (L50)
[2]: 79903b1842/packages/platform-browser-dynamic/test/resource_loader/resource_loader_cache_spec.ts (L37)Fixes#30499
PR Close#30515