chore: Update discovery artifacts (#1407)

## Deleted keys were detected in the following pre-stable discovery artifacts:
analyticsadmin v1alpha https://github.com/googleapis/google-api-python-client/commit/3ed78879365ebef411b2748be8b5d52c047210eb

## Discovery Artifact Change Summary:
feat(analyticsadmin): update the api https://github.com/googleapis/google-api-python-client/commit/3ed78879365ebef411b2748be8b5d52c047210eb
feat(composer): update the api https://github.com/googleapis/google-api-python-client/commit/4862529435851dbb106efa0311c2b7515d2ad2ea
feat(genomics): update the api https://github.com/googleapis/google-api-python-client/commit/8a1c8a67e7e5b76581cfa95ffa14c01019c305af
feat(gkehub): update the api https://github.com/googleapis/google-api-python-client/commit/0fd49e0d39455077e39d850ac464635034d253b8
diff --git a/googleapiclient/discovery_cache/documents/adexchangebuyer.v1.4.json b/googleapiclient/discovery_cache/documents/adexchangebuyer.v1.4.json
index ec82262..dcd72b1 100644
--- a/googleapiclient/discovery_cache/documents/adexchangebuyer.v1.4.json
+++ b/googleapiclient/discovery_cache/documents/adexchangebuyer.v1.4.json
@@ -15,7 +15,7 @@
   "description": "Accesses your bidding-account information, submits creatives for validation, finds available direct deals, and retrieves performance reports.",
   "discoveryVersion": "v1",
   "documentationLink": "https://developers.google.com/ad-exchange/buyer-rest",
-  "etag": "\"uWj2hSb4GVjzdDlAnRd2gbM1ZQ8/dOCFLZ73y7fg6pbfJ8ZiPg3aWe8\"",
+  "etag": "\"uWj2hSb4GVjzdDlAnRd2gbM1ZQ8/g2tPv1tM600rI87F20TINqxamcY\"",
   "icons": {
     "x16": "https://www.google.com/images/icons/product/doubleclick-16.gif",
     "x32": "https://www.google.com/images/icons/product/doubleclick-32.gif"
@@ -1255,7 +1255,7 @@
       }
     }
   },
-  "revision": "20210605",
+  "revision": "20210607",
   "rootUrl": "https://www.googleapis.com/",
   "schemas": {
     "Account": {