Reduce exception wrapping for cleaner stack traces

The StatusRuntimeException often already wraps an IOException, and provides no
value on top of that (because it's created internally in gRPC and has no
relationship to Bazel code). If so, just throw the wrapped IOException directly
to reduce the output spam (if the exception is printed).

Change-Id: Ib2bbad230cf632c491aea0fb24a7721e96178499

Closes #11003.

Change-Id: Ib2bbad230cf632c491aea0fb24a7721e96178499
PiperOrigin-RevId: 302847557

src/main/java/com/google/devtools/build/lib/remote/RemoteServerCapabilities.java

diff --git a/src/main/java/com/google/devtools/build/lib/remote/RemoteServerCapabilities.java b/src/main/java/com/google/devtools/build/lib/remote/RemoteServerCapabilities.java
index 5c87b20..84d3b42 100644
--- a/src/main/java/com/google/devtools/build/lib/remote/RemoteServerCapabilities.java
+++ b/src/main/java/com/google/devtools/build/lib/remote/RemoteServerCapabilities.java
@@ -76,6 +76,9 @@
               : GetCapabilitiesRequest.newBuilder().setInstanceName(instanceName).build();
       return retrier.execute(() -> capabilitiesBlockingStub().getCapabilities(request));
     } catch (StatusRuntimeException e) {
+      if (e.getCause() instanceof IOException) {
+        throw (IOException) e.getCause();
+      }
       throw new IOException(e);
     } finally {
       withMetadata.detach(previous);