Since we are using string.subString(startIndex, endIndex) when parsing

denylist, we should make sure startIndex <= endIndex before calling
string.substring(). Otherwise, an index out of bound excpetion would
throw and make the app terminate. This could happen if we are not
careful with the denylist and make the denylist wrong formatted. For
example, a ";" is left out in the end, and startIndex in this case would
become -1.

When we find the denylist is not properly formatted on framework, we
could print an error in log stating the denylist is wrongly formatted
and go ahead treating this app as not denied.

Test: atest cts/tests/autofillservice/src/android/autofillservice/cts/servicebehavior/AutofillForAllAppsTest.java
Bug:269775456

Change-Id: I7fb87ec18880550a07533d6be079991268120041