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/minimal_jar.bzl b/tools/build/bazel/minimal_jar.bzl
index 6615ec9..2ee40e2 100644
--- a/tools/build/bazel/minimal_jar.bzl
+++ b/tools/build/bazel/minimal_jar.bzl
@@ -22,7 +22,7 @@
         "mkdir readme && touch readme/README && %s cf %s readme/README" % (jar_exe_path, outjar.path),
     ]
 
-    ctx.action(
+    ctx.actions.run_shell(
         outputs = [outjar],
         progress_message = "Generating minimal jar for %s" % ctx.attr.name,
         command = ";\n".join(cmd),