port to androguard >= 4 and drop support for older than 3.3.3

This also makes androguard a hard requirement, which has been true for a
while anyway.  So the code that handles androguard as an optional
requirement is removed.  androguard from Debian/buster is new enough, so
this does not seem like it will cause any problems.

tests/run-tests

@@ -8,7 +8,9 @@ echo_header() {
 
 get_fdroid_apk_filename() {
     if [ -z $aapt ]; then
-        python3 -c "from androguard.core.bytecodes.apk import APK; a=APK('$1'); print(a.package+'_'+a.get_androidversion_code()+'.apk')"
+        appid=$(androguard apkid "$1" | sed -En 's/ +"([a-z][^"]+)",$/\1/ip')
+        versionCode=$(androguard apkid "$1" | sed -En 's/ +"([0-9]+)",$/\1/p')
+        echo "${appid}_${versionCode}.apk"
     else
         $aapt dump badging "$1" | sed -n "s,^package: name='\(.*\)' versionCode='\([0-9][0-9]*\)' .*,\1_\2.apk,p"
     fi

tests/update.TestCase

@@ -5,6 +5,7 @@
 import copy
 import git
 import glob
+import hashlib
 import inspect
 import json
 import logging
@@ -20,11 +21,18 @@ import unittest
 import yaml
 import zipfile
 import textwrap
+from binascii import hexlify
 from datetime import datetime
 from pathlib import Path
 from testcommon import TmpCwd, mkdtemp
 from unittest import mock
 
+try:
+    # these were moved in androguard 4.0
+    from androguard.core.apk import APK
+except ImportError:
+    from androguard.core.bytecodes.apk import APK
+
 try:
     from yaml import CSafeLoader as SafeLoader
 except ImportError:
@@ -581,13 +589,6 @@ class UpdateTest(unittest.TestCase):
         self.assertEqual(good_fingerprint, sig,
                          'python sig was: ' + str(sig))
         # check that v1 and v2 have the same certificate
-        try:
-            import hashlib
-            from binascii import hexlify
-            from androguard.core.bytecodes.apk import APK
-        except ImportError:
-            print('WARNING: skipping rest of test since androguard is missing!')
-            return
         apkobject = APK(apkpath)
         cert_encoded = apkobject.get_certificates_der_v2()[0]
         self.assertEqual(good_fingerprint, sig,