Finish RDE pipeline implementation in SQL mode (#1330)

This PR adds the final step in RDE pipeline (enqueueing the next action
  to Cloud Tasks) and makes some necessary changes, namely by making all
  CloudTasksUtils related classes serializable, so that they can be used
  on Beam.

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core/src/main/resources/google/registry/beam/invoicing_pipeline_metadata.json

@@ -6,9 +6,9 @@
       "name": "registryEnvironment",
       "label": "The Registry environment.",
       "helpText": "The Registry environment, required if environment-specific initialization (such as JPA) is needed on worker VMs.",
-      "is_optional": true,
+      "is_optional": false,
       "regexes": [
-        "^[0-9A-Z_]+$"
+        "^PRODUCTION|SANDBOX|CRASH|QA|ALPHA$"
       ]
     },
     {

core/src/main/resources/google/registry/beam/rde_pipeline_metadata.json

@@ -2,12 +2,21 @@
   "name": "RDE/BRDA Deposit Generation",
   "description": "An Apache Beam pipeline generates RDE or BRDA deposits and deposits them to GCS with GhostRyde encryption.",
   "parameters": [
+    {
+      "name": "registryEnvironment",
+      "label": "The Registry environment.",
+      "helpText": "The Registry environment, required if environment-specific initialization (such as JPA) is needed on worker VMs.",
+      "is_optional": false,
+      "regexes": [
+        "^PRODUCTION|SANDBOX|CRASH|QA|ALPHA$"
+      ]
+    },
     {
       "name": "pendings",
       "label": "The pendings deposits to generate.",
       "helpText": "A TLD to PendingDeposit map that is serialized and Base64 URL-safe encoded.",
       "regexes": [
-        "A-Za-z0-9\\-_"
+        "[A-Za-z0-9\\-_]+"
       ]
     },
     {
@@ -19,12 +28,12 @@
       ]
     },
     {
-      "name": "gcsBucket",
-      "label": "The GCS bucket that where the resulting files will be  stored.",
+      "name": "rdeStagingBucket",
+      "label": "The GCS bucket that where the resulting files will be stored.",
       "helpText": "Only the bucket name itself, without the leading \"gs://\".",
       "is_optional": false,
       "regexes": [
-        "^[a-zA-Z0-9_\\-]+$"
+        "[a-zA-Z0-9_\\-]+$"
       ]
     },
     {
@@ -32,7 +41,7 @@
       "label": "The PGP public key used to encrypt the RDE/BRDA deposit files.",
       "helpText": "The key is Base64 URL-safe encoded.",
       "regexes": [
-        "A-Za-z0-9\\-_"
+        "[A-Za-z0-9\\-_]+"
       ]
     }
   ]

core/src/main/resources/google/registry/beam/spec11_pipeline_metadata.json

@@ -6,9 +6,9 @@
       "name": "registryEnvironment",
       "label": "The Registry environment.",
       "helpText": "The Registry environment, required if environment-specific initialization (such as JPA) is needed on worker VMs.",
-      "is_optional": true,
+      "is_optional": false,
       "regexes": [
-        "^[0-9A-Z_]+$"
+        "^PRODUCTION|SANDBOX|CRASH|QA|ALPHA$"
       ]
     },
     {