Pass through `RUST_LOG`

If the user has RUST_LOG set in the environment, pass that through.

Bug: 352600283
Test: manual
Change-Id: Ia6bfa4be791a8e72591fc729de4e4270df150a1c
diff --git a/ui/build/ninja.go b/ui/build/ninja.go
index b5e74b4..8ca62d3 100644
--- a/ui/build/ninja.go
+++ b/ui/build/ninja.go
@@ -229,6 +229,7 @@
 			"BUILD_BROKEN_INCORRECT_PARTITION_IMAGES",
 			"SOONG_USE_N2",
 			"RUST_BACKTRACE",
+			"RUST_LOG",
 		}, config.BuildBrokenNinjaUsesEnvVars()...)...)
 	}