Force everything to use python3 for consistency.

Rather than "whatever people have installed as 'python' on their machine".

I've removed check-symbols.py because that's been broken for years and
we never even noticed, and I'm not sure it's worth fixing.

Test: treehugger, manual
Change-Id: Ieb996bbdf790a18d4b1fb46a409cc240ba2a2a49
diff --git a/libc/tools/symbols.py b/libc/tools/symbols.py
index 3f40aad..1457534 100644
--- a/libc/tools/symbols.py
+++ b/libc/tools/symbols.py
@@ -41,7 +41,8 @@
 
     symbols = set()
 
-    output = subprocess.check_output(['readelf', sym_type, '-W', elf_file])
+    output = subprocess.check_output(['readelf', sym_type, '-W', elf_file],
+            text=True)
     for line in output.split('\n'):
         if ' HIDDEN ' in line or ' UND ' in line:
             continue
@@ -76,6 +77,10 @@
     if not os.path.isdir(lib_dir):
         lib_dir = os.path.join(out_dir, 'system/lib')
 
+    lib_dir = os.path.join(out_dir, 'apex/com.android.runtime/lib64/bionic/')
+    if not os.path.isdir(lib_dir):
+        lib_dir = os.path.join(out_dir, 'apex/com.android.runtime/lib/bionic/')
+
     results = set()
     for f in files:
         results |= GetFromElf(os.path.join(lib_dir, f))