Modify any lines with libc.so!libc.so to libc.so.

I had made this change if there was an offset on the line,
but I didn't make if there is no offset present. Add the
no offset present case.

Bug: 206463081

Test: Ran unit tests.
Test: Modified a normal stack line with libart.so to be
Test: libart.so!libart.so and verified the line numbers
Test: are still present.
Change-Id: I75e3fbe5eaa3a5419a2dca2c4542731c61c7b971

scripts/stack_core.py

@@ -487,6 +487,13 @@ class TraceConverter:
                 apk = area[0:index + 4]
           if apk:
             lib_name, lib = self.GetLibFromApk(apk, so_offset)
+        else:
+          # Sometimes we'll see something like:
+          #   #01 pc abcd  libart.so!libart.so
+          # Remove everything after the !.
+          index = area.rfind(".so!")
+          if index != -1:
+            area = area[0:index + 3]
         if not lib:
           lib = area
           lib_name = None