This book is really, really bad. If you're interested in learning about developing secure Android apps, find something else, because this is not what you're looking for.
I'm going to list my categories of objections here, in descending order of importance: - it's riddled with blatant falsehoods. The author gets very basic things about the Android OS wrong. - it's full of code samples that you should definitely not use. Printing code that bad in a textbook, as though it should be copied, is irresponsible. - it hand-waves past most topics that could be actually useful. - there are two "case studies" in the back, both of which are about Blackberry malware. That has literally nothing to do with the topic of the book. - it's out of date, having been published in 2012. Not the author's fault, but the Android OS has come a long way since then. - least importantly, the writing itself is pretty bad.