CI: Add agent attribute with queue android to every yml file

With that change all the steps in those YML pipelines would build on our
Android queue by default.

FYI: The below '.buildkite/**/*.yml' file were already using this agent:
- pipeline.yml
- schedules/dependency-analysis.yml

For more info see: Automattic/buildkite-ci#459
#issuecomment-2199589109

.buildkite/beta-builds.yml

@@ -7,6 +7,9 @@ common_params:
   - &common_plugins
     - automattic/a8c-ci-toolkit#3.4.2
 
+agents:
+  queue: "android"
+
 steps:
   #################
   # Gradle Wrapper Validation

.buildkite/code-freeze.yml

@@ -4,6 +4,9 @@ common_params:
   - &common_plugins
     - automattic/a8c-ci-toolkit#3.4.2
 
+agents:
+  queue: "android"
+
 steps:
   - label: "Code Freeze"
     plugins: *common_plugins

.buildkite/complete-code-freeze.yml

@@ -4,6 +4,9 @@ common_params:
   - &common_plugins
     - automattic/a8c-ci-toolkit#3.4.2
 
+agents:
+  queue: "android"
+
 steps:
   - label: "Complete Code Freeze"
     plugins: *common_plugins

.buildkite/finalize-release.yml

@@ -4,6 +4,9 @@ common_params:
   - &common_plugins
     - automattic/a8c-ci-toolkit#3.4.2
 
+agents:
+  queue: "android"
+
 steps:
   - label: "Finalize release"
     plugins: *common_plugins

.buildkite/new-beta-release.yml

@@ -4,6 +4,9 @@ common_params:
   - &common_plugins
     - automattic/a8c-ci-toolkit#3.4.2
 
+agents:
+  queue: "android"
+
 steps:
   - label: "New Beta Release"
     plugins: *common_plugins

.buildkite/release-builds.yml

@@ -7,6 +7,9 @@ common_params:
   - &common_plugins
     - automattic/a8c-ci-toolkit#3.4.2
 
+agents:
+  queue: "android"
+
 steps:
   #################
   # Gradle Wrapper Validation

.buildkite/update-release-notes.yml

@@ -4,6 +4,9 @@ common_params:
   - &common_plugins
     - automattic/a8c-ci-toolkit#3.4.2
 
+agents:
+  queue: "android"
+
 steps:
   - label: "Update release notes"
     plugins: *common_plugins