Renaming the virtual device Nexus5 name to Nexus5.gce_x86 (#145225)

This is required to match a rename being made for the devices in firebase lab.

Also removed `version=24` entry, since thats not supported on Nexus5x, per the firebase team.

Bug:b/322830672

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*List which issues are fixed by this PR. You must list at least one issue. An issue is not required if the PR fixes something trivial like a typo.*

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.ci.yaml

@@ -523,10 +523,9 @@ targets:
       # "--device", "model=Nexus6P,version=25"
       virtual_devices: >-
         [
-          "--device", "model=Nexus5,version=21",
-          "--device", "model=Nexus5,version=22",
-          "--device", "model=Nexus5,version=23",
-          "--device", "model=Nexus5,version=24",
+          "--device", "model=Nexus5.gce_x86,version=21",
+          "--device", "model=Nexus5.gce_x86,version=22",
+          "--device", "model=Nexus5.gce_x86,version=23",
           "--device", "model=Nexus6P,version=25",
           "--device", "model=Nexus6P,version=26",
           "--device", "model=Nexus6P,version=27",
@@ -555,9 +554,9 @@ targets:
       # "--device", "model=Nexus6P,version=25"
       virtual_devices: >-
         [
-          "--device", "model=Nexus5,version=21",
-          "--device", "model=Nexus5,version=22",
-          "--device", "model=Nexus5,version=23",
+          "--device", "model=Nexus5.gce_x86,version=21",
+          "--device", "model=Nexus5.gce_x86,version=22",
+          "--device", "model=Nexus5.gce_x86,version=23",
           "--device", "model=Nexus6P,version=25",
           "--device", "model=Nexus6P,version=26",
           "--device", "model=Nexus6P,version=27",
@@ -586,9 +585,9 @@ targets:
       # "--device", "model=Nexus6P,version=25"
       virtual_devices: >-
         [
-          "--device", "model=Nexus5,version=21",
-          "--device", "model=Nexus5,version=22",
-          "--device", "model=Nexus5,version=23",
+          "--device", "model=Nexus5.gce_x86,version=21",
+          "--device", "model=Nexus5.gce_x86,version=22",
+          "--device", "model=Nexus5.gce_x86,version=23",
           "--device", "model=Nexus6P,version=25",
           "--device", "model=Nexus6P,version=26",
           "--device", "model=Nexus6P,version=27",