servo: Merge #13946 - Update `etc/ci/check_dynamic_symbols.py` (from mmatyas:android_dyncheck); r=larsbergstrom

Update `etc/ci/check_dynamic_symbols.py` to work after [the latest changes](https://github.com/servo/servo/pull/13945) in the Android build system.

Part of #13154.

Source-Repo: https://github.com/servo/servo
Source-Revision: b661f0691611c8c568840b75ac646af960aa683d

servo/etc/ci/check_dynamic_symbols.py

@@ -9,16 +9,19 @@
 
 from __future__ import absolute_import, print_function
 
-import sys
+import os
 import re
 import subprocess
+import sys
 
 symbol_regex = re.compile(b"D  \*UND\*\t(.*) (.*)$")
 allowed_symbols = frozenset([b'unshare', b'malloc_usable_size'])
 actual_symbols = set()
 
 objdump_output = subprocess.check_output([
-    'arm-linux-androideabi-objdump',
+    os.path.join(
+        os.environ['ANDROID_NDK'], 'toolchains', 'arm-linux-androideabi-4.9',
+        'prebuilt', 'linux-x86_64', 'bin', 'arm-linux-androideabi-objdump'),
     '-T',
     'target/arm-linux-androideabi/debug/libservo.so']
 ).split(b'\n')