gn2bp: fix jni_generator --includes

Test: //base:base
Change-Id: I66c34ac0fd9384f0430ab98c7d21541eeaaf4f71
diff --git a/tools/gn2bp/gen_android_bp b/tools/gn2bp/gen_android_bp
index 2da4142..61cd964 100755
--- a/tools/gn2bp/gen_android_bp
+++ b/tools/gn2bp/gen_android_bp
@@ -701,6 +701,9 @@
         # TODO: put inside function
         filename = re.sub('^\.\./\.\./', '', target.args[i + 1])
         target.args[i + 1] = '$(location %s)' % filename
+      if val == '--includes' and 'jni_generator_helper' in target.args[i + 1]:
+        # delete all leading ../
+        target.args[i + 1] = re.sub('^(\.\./)+', '', target.args[i + 1])
     # fix target.output directory to match #include statements.
     target.outputs = [re.sub('^jni_headers/', '', out) for out in target.outputs]