Add flag --remote_download_all in spirit of --remote_download_[toplevel|minimal].

A following CL changes the default value of `--remote_download_outputs` to `toplevel`. This CL adds a convinent flag to allow users download all outputs.

PiperOrigin-RevId: 543386266
Change-Id: If53c50a6371e3437fe661c255452442df3cdc97f

Author: coeuvre

src/main/java/com/google/devtools/build/lib/remote/options/RemoteOptions.java

@@ -486,6 +486,18 @@ public RemoteOutputsStrategyConverter() {
               + " alias for flag --remote_download_outputs=toplevel.")
   public Void remoteOutputsToplevel;
 
+  @Option(
+      name = "remote_download_all",
+      defaultValue = "null",
+      expansion = {"--remote_download_outputs=all"},
+      category = "remote",
+      documentationCategory = OptionDocumentationCategory.OUTPUT_PARAMETERS,
+      effectTags = {OptionEffectTag.AFFECTS_OUTPUTS},
+      help =
+          "Downloads all remote outputs to the local machine. This flag is an alias for flag"
+              + " --remote_download_outputs=all.")
+  public Void remoteOutputsAll;
+
   @Option(
       name = "remote_result_cache_priority",
       defaultValue = "0",