Docker build environment protoc is not executable

I tried to run some tests using the Docker build environment and hit this:

$ ./gradlew -p sdks/java/io/cassandra check
Starting a Gradle Daemon, 1 incompatible and 1 stopped Daemons could
not be reused, use \--status for details
Configuration on demand is an incubating feature.
\> Task :model:pipeline:generateProto FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':model:pipeline:generateProto'.
\> java.io.IOException: Cannot run program "/home/elharo/.gradle/caches/modules-2/files-2.1/com.google.protobuf/protoc/3.15.3/8fb78f9edc8192143d947edc2217aafaa5d5f79b/protoc-3.15.3-linux-x86_64.exe": error=13, Permission denied

  I do see that protoc does not have execute permission:

$ ls -l /home/elharo/.gradle/caches/modules-2/files-2.1/com.google.protobuf/protoc/3.15.3/8fb78f9edc8192143d947edc2217aafaa5d5f79b/
total 5120
-rw-r\--r\-- 1 elharo users 5241944 Apr  9 22:17 protoc-3.15.3-linux-x86_64.exe{color:#888888}

{color}

Imported from Jira [BEAM-12149](https://issues.apache.org/jira/browse/BEAM-12149). Original Jira may contain additional context.
Reported by: elharo.