Changed to use ctx.actions.run_shell instead of ctx.action

The 'action' attribute was depricated and finally removed probably at
the Bazel 3.4.0 release.

Change-Id: I2aafae3e780b8e68a3ad9a162d62210743f9f2fd
diff --git a/tools/build/bazel/java_sources.bzl b/tools/build/bazel/java_sources.bzl
index 1381a05..0220919 100644
--- a/tools/build/bazel/java_sources.bzl
+++ b/tools/build/bazel/java_sources.bzl
@@ -29,7 +29,7 @@
         "[ -n \"$dir\" -a -d \"$dir\" ] && %s cf %s -C $dir ." % (jar_path, outjar.path),
     ]
 
-    ctx.action(
+    ctx.actions.run_shell(
         inputs = ctx.files.srcs,
         outputs = [outjar],
         progress_message = "Generating source jar for %s" % ctx.attr.name,