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/javadoc.bzl b/tools/build/bazel/javadoc.bzl
index 6493160..b9f514c 100644
--- a/tools/build/bazel/javadoc.bzl
+++ b/tools/build/bazel/javadoc.bzl
@@ -36,7 +36,7 @@
         "%s cf %s -C %s ." % (jar_exe_path, outjar.path, dir),
     ]
 
-    ctx.action(
+    ctx.actions.run_shell(
         inputs = ctx.files.srcs + ctx.files.deps,
         outputs = [outjar],
         progress_message = "Generating javadocs jar for %s" % ctx.attr.name,