[cipd] Bump CIPD client version to 2.2.8, add presubmit check for *.digests.

The new version uses SHA256 for uploads by default. It also fully supports
$ResolvedVersions and 'selfupdate-roll'.

The roll was generated by:
$ ./cipd selfupdate-roll \
  -version-file cipd_client_version \
  -version git_revision:fb963f0f43e265a65fb7f1f202e17ea23e947063

BUG=821194, 870166
R=nodir@chromium.org, iannucci@chromium.org

Change-Id: If7c23c43ff2c1bf50c9c50f4e9e17a23e84859b9
Reviewed-on: https://chromium-review.googlesource.com/1227431
Commit-Queue: Vadim Shtayura <vadimsh@chromium.org>
Reviewed-by: Nodir Turakulov <nodir@chromium.org>

PRESUBMIT.py

@@ -105,6 +105,8 @@ def CommonChecks(input_api, output_api, tests_to_black_list):
       tests.append(input_api.canned_checks.CheckCIPDManifest(
           input_api, output_api,
           content=CIPD_CLIENT_ENSURE_FILE_TEMPLATE % (pkg, ver)))
+      tests.append(input_api.canned_checks.CheckCIPDClientDigests(
+          input_api, output_api, client_version_file=path))
 
   results.extend(input_api.RunTests(tests))
   return results

cipd_client_version

-git_revision:ea6c07cfcb596be6b63a1e6deb95bba79524b0c8
+git_revision:fb963f0f43e265a65fb7f1f202e17ea23e947063

cipd_client_version.digests

 # This file was generated by
 #
 #  cipd selfupdate-roll -version-file cipd_client_version \
-#      -version git_revision:ea6c07cfcb596be6b63a1e6deb95bba79524b0c8
+#      -version git_revision:fb963f0f43e265a65fb7f1f202e17ea23e947063
 #
 # Do not modify manually. All changes will be overwritten.
 # Use 'cipd selfupdate-roll ...' to modify.
 
-linux-386       sha256  ee90bd655b90baf7586ab80c289c00233b96bfac3fa70e64cc5c48feb1998971
-linux-amd64     sha256  73bd62cb72cde6f12d9b42cda12941c53e1e21686f6f2b1cd98db5c6718b7bed
-linux-arm64     sha256  1f2619f3e7f5f6876d0a446bacc6cc61eb32ca1464315d7230034a832500ed64
-linux-armv6l    sha256  98c873097c460fe8f6b4311f6e00b4df41ca50e9bd2d26f06995913a9d647d3a
-linux-mips64    sha256  05e37c85502eb2b72abd8a51ff13a4914c5e071e25326c9c8fc257290749138a
-linux-mips64le  sha256  5b3af8be6ea8a62662006f1a86fdc387dc765edace9f530acbeca77c0850a32d
-linux-mipsle    sha256  cfa6539af00db69b7da00d46316f1aaaa90b38a5e6b33ce4823be17533e71810
-linux-ppc64     sha256  faa49f2b59a25134e8a13b68f5addb00c434c7feeee03940413917eca1d333e6
-linux-ppc64le   sha256  6fa51348e6039b864171426b02cfbfa1d533b9f86e3c72875e0ed116994a2fec
-linux-s390x     sha256  6cd4bfff7e2025f2d3da55013036e39eea4e8f631060a5e2b32b9975fab08b0e
-mac-amd64       sha256  6427b87fdaa1615a229d45c2fab1ba7fdb748ce785f2c09cd6e10adc48c58a66
-windows-386     sha256  809c727a31e5f8c34656061b96839fbca63833140b90cab8e2491137d6e4fc4c
-windows-amd64   sha256  3e21561b45acb2845c309a04cbedb2ce1e0567b7b24bf89857e7673607b09216
+linux-386       sha256  4e488d22d03e44fb1c24bbe192575970b3898ba5fc3d3ac9751545ee90b727e5
+linux-amd64     sha256  f6bd33252d7f9eb93718b2808b66db012416c0bd0b7ba4670d3f56670782f07a
+linux-arm64     sha256  233c24311443873ec14d96d0f8e3a70a533f1ee4cb36c26fad1fd127834a28d9
+linux-armv6l    sha256  1b5c6eea7fa4cabb7b82bb8666b3762b5e50bbe4ed39c1321b89927faebb4b0a
+linux-mips64    sha256  0e7863521601eb5581c2a00440797f04413c3f8da6392d3429289c06ff8aadcf
+linux-mips64le  sha256  09cabd05ce48dee62f5cb516ca1f4eca9986dcb5880f6af7dd28c324dd000b0e
+linux-mipsle    sha256  e229160b2b46cd6b8cf9d8343a85d5d00dd11e72574913353bd76c76dfee4ebd
+linux-ppc64     sha256  79c075c274b8d0be000b35bcec40f73ed50b0354ab4d99536fbb011c5dc1986b
+linux-ppc64le   sha256  32c486e6c06361b40e0c42ef6645591dd988000e4ec8f004ea43255b4c9b3628
+linux-s390x     sha256  80d990b0c69b522d563f7e367dda0987e6bb1936d6ca2ae33d985ed706cb661b
+mac-amd64       sha256  525186502934af16f8fe5c4cf35588b3886285043c269c63d937c2d780639139
+windows-386     sha256  8baf18b295cd377265e021a026b978c82833b0e62944a6050ce735a6a1652008
+windows-amd64   sha256  b7b31cfd3f6bb8e0bc3fdb1c394987ce0a2a785f4dd9b850f45b1199f9a97e72