Go one directory up looking for releasetools path

Change I366099c3dfd5fa4282745ef258a8cf35338e1e42 introduced a more
restricted search where we only look in out/host/x/bin instead of
out/host/x when looking for files.

Because signapk is in out/host/x/framework, and lib64 is in out/host/x,
we need to go one level up for this to work properly.

Fix: 147096688
Test: atest --host releasetools_test releasetools_py3_test
Change-Id: I597e1d95c09eb0e27b2faebb107218761901d9ac

tools/releasetools/common.py

@@ -62,7 +62,7 @@ class Options(object):
           'Warning: releasetools script should be invoked as hermetic Python '
           'executable -- build and run `{}` directly.'.format(script_name[:-3]),
           file=sys.stderr)
-    self.search_path = os.path.realpath(os.path.join(exec_path, '..'))
+    self.search_path = os.path.realpath(os.path.join(os.path.dirname(exec_path), '..'))
 
     self.signapk_path = "framework/signapk.jar"  # Relative to search_path
     self.signapk_shared_library_path = "lib64"   # Relative to search_path