creating a single target to rollup maven artifacts (#8776)

java/BUILD

@@ -6,3 +6,11 @@ test_suite(
         "//java/util:tests",
     ],
 )
+
+filegroup(
+    name = "release",
+    srcs = [
+        "//java/core:release", # contains lite.
+        "//java/util:release",
+    ]
+)

java/core/BUILD

@@ -142,6 +142,21 @@ java_export(
     ],
 )
 
+filegroup(
+    name = "release",
+    visibility = ["//java:__pkg__"],
+    srcs = [
+        ":core-pom",
+        ":core-maven-source",
+        ":core-docs",
+        ":core-project",
+        ":lite-pom",
+        ":lite-maven-source",
+        ":lite-docs",
+        ":lite-project",
+    ]
+)
+
 proto_lang_toolchain(
     name = "toolchain",
     command_line = "--java_out=$(OUT)",

java/util/BUILD

@@ -20,6 +20,17 @@ java_export(
     ],
 )
 
+filegroup(
+    name = "release",
+    visibility = ["//java:__pkg__"],
+    srcs = [
+        ":util-pom",
+        ":util-maven-source",
+        ":util-docs",
+        ":util-project",
+    ]
+)
+
 proto_library(
     name = "test_protos",
     srcs = glob(["src/test/proto/**/*.proto"]),