Revert^2 "Fix signing failure for split APKs"

This reverts commit d06e5a83ba7065afd874f9f8589118e5f34cec17.

Reason for revert: <It's not a culprit any more.>

Change-Id: I405c418e6da88774b174fcb3508eb54039fbdf8e
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 4834834..f6f6944 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -2434,12 +2434,23 @@
         "Failed to obtain minSdkVersion for {}: aapt2 return code {}:\n{}\n{}".format(
             apk_name, proc.returncode, stdoutdata, stderrdata))
 
+  is_split_apk = False
   for line in stdoutdata.split("\n"):
+    # See b/353837347 , split APKs do not have sdk version defined,
+    # so we default to 21 as split APKs are only supported since SDK
+    # 21.
+    if (re.search(r"split=[\"'].*[\"']", line)):
+      is_split_apk = True
     # Due to ag/24161708, looking for lines such as minSdkVersion:'23',minSdkVersion:'M'
     # or sdkVersion:'23', sdkVersion:'M'.
     m = re.match(r'(?:minSdkVersion|sdkVersion):\'([^\']*)\'', line)
     if m:
       return m.group(1)
+  if is_split_apk:
+    logger.info("%s is a split APK, it does not have minimum SDK version"
+                " defined. Defaulting to 21 because split APK isn't supported"
+                " before that.", apk_name)
+    return 21
   raise ExternalError("No minSdkVersion returned by aapt2 for apk: {}".format(apk_name))