Put the @Nullable annotation before any modifiers (per the style guide).

The upcoming unknown commit copy/pasted lines from these files and
triggered a lint warning about this, so let's just fix all other
instances of the same issue.

RELNOTES: None.
PiperOrigin-RevId: 299840548

src/main/java/com/google/devtools/build/lib/sandbox/DarwinSandboxedSpawnRunner.java

diff --git a/src/main/java/com/google/devtools/build/lib/sandbox/DarwinSandboxedSpawnRunner.java b/src/main/java/com/google/devtools/build/lib/sandbox/DarwinSandboxedSpawnRunner.java
index 685e6ff..329df1b 100644
--- a/src/main/java/com/google/devtools/build/lib/sandbox/DarwinSandboxedSpawnRunner.java
+++ b/src/main/java/com/google/devtools/build/lib/sandbox/DarwinSandboxedSpawnRunner.java
@@ -104,7 +104,7 @@
   private final Path processWrapper;
   private final Path sandboxBase;
   private final Duration timeoutKillDelay;
-  private final @Nullable SandboxfsProcess sandboxfsProcess;
+  @Nullable private final SandboxfsProcess sandboxfsProcess;
   private final boolean sandboxfsMapSymlinkTargets;
   private final TreeDeleter treeDeleter;
 

src/main/java/com/google/devtools/build/lib/sandbox/LinuxSandboxedSpawnRunner.java

diff --git a/src/main/java/com/google/devtools/build/lib/sandbox/LinuxSandboxedSpawnRunner.java b/src/main/java/com/google/devtools/build/lib/sandbox/LinuxSandboxedSpawnRunner.java
index f95b528..50ee1ed 100644
--- a/src/main/java/com/google/devtools/build/lib/sandbox/LinuxSandboxedSpawnRunner.java
+++ b/src/main/java/com/google/devtools/build/lib/sandbox/LinuxSandboxedSpawnRunner.java
@@ -95,7 +95,7 @@
   private final Path inaccessibleHelperDir;
   private final LocalEnvProvider localEnvProvider;
   private final Duration timeoutKillDelay;
-  private final @Nullable SandboxfsProcess sandboxfsProcess;
+  @Nullable private final SandboxfsProcess sandboxfsProcess;
   private final boolean sandboxfsMapSymlinkTargets;
   private final TreeDeleter treeDeleter;