Update `SpringBootContextLoader` to both add `spring.profiles.active`
properties and to directly call `Environment.setActiveProfiles`.
The additional `setActiveProfiles` call prevents `AbstractEnvironment`
from accidentally loading `spring.profiles.active` properties directly
when `doGetActiveProfiles` is called.
Directly setting active profiles has only become necessary since we
started adding properties using the square bracket notation. Previously
we added a comma-separated list which would be picked up by both the
`AbstractEnvironment` and the `ConfigurationFileApplicationListener`.
Closes gh-21302
49921d65ac