Update docs on running single tests

The examples refer to running a single test, but the `-run` command
example could potentially run lots of tests unexpectedly.

Use a `-run=` example with the correct syntax for passing a literal
dollar sign to the regex -- while the docs link to the golang docs,
because of shell quoting and because of it getting passed via make, it
seems to be necessary to use double dollar signs.

Fixes hashicorp/terraform-provider-google#19934

docs/content/code-review/create-pr.md

@@ -52,7 +52,7 @@ VCR test failures that do not immediately seem related to your PR are most likel
    git checkout modular-magician/auto-pr-PR_NUMBER
    make test
    make lint
-   make testacc TEST=./google/services/container TESTARGS='-run=TestAccContainerNodePool'
+   make testacc TEST=./google/services/container TESTARGS='-run=TestAccContainerNodePool_basic$$'
    ```
    Replace PR_NUMBER with your PR's ID.
    {{< /tab >}}
@@ -65,7 +65,7 @@ VCR test failures that do not immediately seem related to your PR are most likel
    git checkout modular-magician/auto-pr-PR_NUMBER
    make test
    make lint
-   make testacc TEST=./google/services/container TESTARGS='-run=TestAccContainerNodePool'
+   make testacc TEST=./google/services/container TESTARGS='-run=TestAccContainerNodePool_basic$$'
    ```
    Replace PR_NUMBER with your PR's ID.
    {{< /tab >}}

docs/content/test/run-tests.md

@@ -60,15 +60,15 @@ aliases:
 1. Run acceptance tests for only modified resources. (Full test runs can take over 9 hours.) See [Go's documentation](https://pkg.go.dev/cmd/go#hdr-Testing_flags) for more information about `-run` and other flags.
 
     ```bash
-    make testacc TEST=./google/services/container TESTARGS='-run=TestAccContainerNodePool'
+    make testacc TEST=./google/services/container TESTARGS='-run=TestAccContainerNodePool_basic$$'
     ```
 
 > **Note:** Acceptance tests create actual infrastructure which can incur costs. Acceptance tests may not clean up after themselves if interrupted, so you may want to check for stray resources and / or billing charges.
 
 1. Optional: Save verbose test output (including API requests and responses) to a file for analysis.
 
     ```bash
-    TF_LOG=DEBUG make testacc TEST=./google/services/container TESTARGS='-run=TestAccContainerNodePool_basic' > output.log
+    TF_LOG=DEBUG make testacc TEST=./google/services/container TESTARGS='-run=TestAccContainerNodePool_basic$$' > output.log
     ```
 
 1. Optional: Debug tests with [Delve](https://github.com/go-delve/delve). See [`dlv test` documentation](https://github.com/go-delve/delve/blob/master/Documentation/usage/dlv_test.md) for information about available flags.
@@ -100,7 +100,7 @@ aliases:
 1. Optional: Save verbose test output to a file for analysis.
 
     ```bash
-    TF_LOG=DEBUG make testacc TEST=./google-beta/services/container TESTARGS='-run=TestAccContainerNodePool_basic' > output.log
+    TF_LOG=DEBUG make testacc TEST=./google-beta/services/container TESTARGS='-run=TestAccContainerNodePool_basic$$' > output.log
     ```
 
 1. Optional: Debug tests with [Delve](https://github.com/go-delve/delve). See [`dlv test` documentation](https://github.com/go-delve/delve/blob/master/Documentation/usage/dlv_test.md) for information about available flags.