graphics/results_database: Update README.md with google cloud pip install.

BUG=None
TEST=None

Change-Id: I3e416241becabffe933994aec266f2e3f6091cfd
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/graphics/+/2442034
Tested-by: David Riley <davidriley@chromium.org>
Auto-Submit: David Riley <davidriley@chromium.org>
Reviewed-by: Georges Winkenbach <gwink@chromium.org>
Commit-Queue: Georges Winkenbach <gwink@chromium.org>
diff --git a/src/results_database/README.md b/src/results_database/README.md
index 7449709..5a9a2e5 100644
--- a/src/results_database/README.md
+++ b/src/results_database/README.md
@@ -11,6 +11,7 @@
 popd /dev/null
 
 pip3 install .
+pip3 install install --upgrade google-cloud-bigquery
 
 PATH=$PATH:$PWD/src/platform/graphics/src/results_database
 ```