docs: update set up workstation how-to (#11478)

* Update doc to handle x86_64 (uname -p produces unknown for x86_64 on my VM)
* Add sudo before running the install google sdk script so the mkdir commands can create directories
* Add a note about setting the env variables
* Add a note about installing clangtidy in newer versions of ubuntu

ci/install-cloud-sdk.sh

@@ -22,7 +22,7 @@ declare -A -r GOOGLE_CLOUD_CPP_SDK_SHA256=(
   ["arm"]="d3d7d8bdde1abc8e8279b813b3341d20fa3af1928268d97c61b0553a8e590124"
 )
 
-ARCH="$(uname -p)"
+ARCH="$(uname -m)"
 if [[ "${ARCH}" == "aarch64" ]]; then
   # The tarball uses this name
   ARCH="arm"

doc/contributor/howto-guide-setup-cmake-environment.md

@@ -87,6 +87,12 @@ env -C build-out/home ctest --output-on-failure -LE integration-test
 If you also want to run the integration tests you need to setup multiple
 [environment variables](/ci/etc/integration-tests-config.sh), and then run:
 
+To set up the environment variables, run the script using:
+
+```shell
+source ci/etc/integration-tests-config.sh
+```
+
 ```shell
 env -C build-out/home ctest --output-on-failure
 ```

doc/contributor/howto-guide-setup-development-workstation.md

@@ -61,6 +61,12 @@ sudo update-alternatives --install /usr/bin/clang-tidy clang-tidy /usr/bin/clang
 sudo update-alternatives --install /usr/bin/clang-format clang-format /usr/bin/clang-format-10 100
 ```
 
+Note: newer versions of Ubuntu might require:
+
+```console
+sudo apt install -y clang libc++-dev libc++abi-dev cmake ninja-build
+```
+
 Install the buildifier tool, which we use to format `BUILD.bazel` files:
 
 ```console
@@ -127,7 +133,7 @@ on the [Google Cloud SDK website](https://cloud.google.com/sdk/) for
 alternatives.
 
 ```console
-./ci/install-cloud-sdk.sh
+sudo ./ci/install-cloud-sdk.sh
 ```
 
 ### (Optional) Enable clang-based tooling in your IDE