Update toolchain config to allow reflective access to `com.sun.tools.javac.parser`

Reported here: https://github.com/google/error-prone/issues/2271#issuecomment-1018294740

PiperOrigin-RevId: 423272568
diff --git a/tools/jdk/default_java_toolchain.bzl b/tools/jdk/default_java_toolchain.bzl
index ac8ed5d..14479d4 100644
--- a/tools/jdk/default_java_toolchain.bzl
+++ b/tools/jdk/default_java_toolchain.bzl
@@ -24,7 +24,6 @@
     "--add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED",
     "--add-exports=jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED",
     "--add-exports=jdk.compiler/com.sun.tools.javac.model=ALL-UNNAMED",
-    "--add-exports=jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED",
     "--add-exports=jdk.compiler/com.sun.tools.javac.processing=ALL-UNNAMED",
     "--add-exports=jdk.compiler/com.sun.tools.javac.resources=ALL-UNNAMED",
     "--add-exports=jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED",
@@ -32,6 +31,7 @@
     "--add-opens=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED",
     "--add-opens=jdk.compiler/com.sun.tools.javac.comp=ALL-UNNAMED",
     "--add-opens=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED",
+    "--add-opens=jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED",
 
     # quiet warnings from com.google.protobuf.UnsafeUtil,
     # see: https://github.com/google/protobuf/issues/3781