Use buildOrThrow instead of build for ImmutableMap.

[rlazo]

This method have been added in guava 31, so we are also updating the dependency.

[google-oss-bot]

Size Report ¹

Affected Products

No changes between base commit (2db9b55) and merge commit (f26c9c3).

Test Logs

• Base (2db9b55): https://android-ci.firebaseopensource.com/view/gcs/android-ci/logs/postsubmit-binary-size/1488964504552214529
• Merge (f26c9c3): https://android-ci.firebaseopensource.com/view/gcs/android-ci/pr-logs/pull/firebase_firebase-android-sdk/3394/binary-size/1489069136838397952

Notes

• Commit (f26c9c3) is created by Prow via merging PR base commit (2db9b55) and head commit (ab7862a).

1. https://storage.googleapis.com/firebase-sdk-metric-reports/xd4SdqeNE0.html

[google-oss-bot]

Coverage Report ¹

Affected Products

No changes between base commit (2db9b55) and merge commit (f26c9c3).

Test Logs

• Base (2db9b55): https://android-ci.firebaseopensource.com/view/gcs/android-ci/logs/postsubmit-check-coverage/1488964504552214530
• Merge (f26c9c3): https://android-ci.firebaseopensource.com/view/gcs/android-ci/pr-logs/pull/firebase_firebase-android-sdk/3394/check-coverage-changed/1489069136834203652

Notes

• Commit (f26c9c3) is created by Prow via merging PR base commit (2db9b55) and head commit (ab7862a).
• Run gradle <product>:checkCoverage to produce HTML coverage reports locally. After gradle commands finished, report files can be found under <product-build-dir>/reports/jacoco/.

1. https://storage.googleapis.com/firebase-sdk-metric-reports/aQZKOPGZOW.html