[roll third_party/pigweed] build: Build for Java 11

For some reason, the language version of Java was defaulting to 8 rather
than 11. This explicitly sets the language version to match the SDK
version to silence warnings about Java 8 being deprecated.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/191830

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 6ed0c3ade7a7e00..6d845436cea4a45
Roller-URL: https://ci.chromium.org/b/8756257886523065073
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ia366983af22b32a6147bd8b1665e7fa3cd0a3568
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/191799
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 6ed0c3a..6d84543 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 6ed0c3ade7a7e008e317ed2a7aef48260c346397
+Subproject commit 6d845436cea4a455711e7eea4661d5e0965b612c