Rename `rules_java` runfiles package `BUILD.bazel` -> `BUILD`

Work towards https://github.com/bazelbuild/bazel/pull/24394

PiperOrigin-RevId: 700322638
Change-Id: Ic8af8b0bb8ad82f0e89c87b3ccb84d44b89067c5

java/runfiles/BUILD

diff --git a/java/runfiles/BUILD.bazel b/java/runfiles/BUILD
similarity index 100%
rename from java/runfiles/BUILD.bazel
rename to java/runfiles/BUILD

java/runfiles/src/main/java/com/google/devtools/build/runfiles/BUILD

diff --git a/java/runfiles/src/main/java/com/google/devtools/build/runfiles/BUILD.bazel b/java/runfiles/src/main/java/com/google/devtools/build/runfiles/BUILD
similarity index 90%
rename from java/runfiles/src/main/java/com/google/devtools/build/runfiles/BUILD.bazel
rename to java/runfiles/src/main/java/com/google/devtools/build/runfiles/BUILD
index a2563d9..ee1bd83 100644
--- a/java/runfiles/src/main/java/com/google/devtools/build/runfiles/BUILD.bazel
+++ b/java/runfiles/src/main/java/com/google/devtools/build/runfiles/BUILD
@@ -1,4 +1,4 @@
-load("@rules_java//java:defs.bzl", "java_library", "java_plugin")
+load("//java:defs.bzl", "java_library", "java_plugin")
 
 java_library(
     name = "runfiles",