maven_install is strongly superior to previous forms of grabbing dependencies
from Maven as it computes the appropriate versions to use from the full
transitive dependencies of all libraries used by an application. It also has
much less boilerplate and includes dependencies with generated targets.
In the future we will drop the jvm_maven_import_external usages and require
maven_install, at which point we can swap to using the `@maven' repository and
no longer depend on compat_repositories.
Fixes#5359
They were removed in 137c74d1 since it was believed they were unnecessary.
However, since they are in a macro and not a rule, they are relative to the
caller, not their definition.
Added building the examples to the kokoro CI. Note that this means the examples
are built twice: once in grpc-java's build and once in their own (because it
has a WORKSPACE). Given that the Bazel build is our fastest build, this
slowdown won't probably be an issue.