See gh-12028

Closes gh-12320
See gh-12028

See gh-12028

See gh-12028

Closes gh-12028

Closes gh-12316

Closes gh-12314

Closes gh-12315

This commit moves the Java9-specific profile to each sample rather than
impacting all samples. That way, affected samples are more self
contained.

Closes gh-12302

* pr/12295:
  Make UserDetailsServiceAutoConfiguration.getOrDeducePassword() private

Closes gh-12295

* pr/12304:
  Polish

Replace class "Stack" by more modern "Deque"

Closes gh-12304

Closes gh-10456

Closes gh-12297

See gh-12293

As of AspectJ 1.8.13, the override is no longer necessary to build
the samples.

See gh-11095

Closes gh-10456

Closes gh-12293

Update flattened POM rules to satisfy maven central
requirements.

Fixes gh-12290

Fixes gh-12291

Closes gh-12235

This reverts commit eef6fdb0.

* gh-12287:
  Polish "Remove redundant auto-configuration of SI Micrometer metrics"
  Remove redundant auto-configuration of SI Micrometer metrics

Closes gh-12287

Spring Integration no longer requires a `MicrometerMetricsFactory` to
support Micrometer metrics so there's nothing for Boot to
auto-configure.

See gh-12287

Closes gh-12286

Fixes gh-12267