Don't print a line if aflags output is empty

Bug: 385136353
Test: m
Change-Id: I1f7d6d1d65375c5a2927b58bd87fed82e602ac0c
diff --git a/tools/aconfig/aflags/src/main.rs b/tools/aconfig/aflags/src/main.rs
index e4af2a7..568ad99 100644
--- a/tools/aconfig/aflags/src/main.rs
+++ b/tools/aconfig/aflags/src/main.rs
@@ -320,7 +320,10 @@
         .wait_with_output()
         .expect("failed to execute command");
 
-    println!("{}", String::from_utf8_lossy(&output.stdout).trim());
+    let output_str = String::from_utf8_lossy(&output.stdout).trim().to_string();
+    if !output_str.is_empty() {
+        println!("{}", output_str);
+    }
 }
 
 fn main() -> Result<()> {