SQLite has a very nice "EXPLAIN QUERY PLAN" command (https://sqlite.org/eqp.html).
It is not really meant to be used in production code, as per the docs, but it is
super helpful at diagnosing missing indexes or other performance problems with
databases. I find it much better than, for example, the MySQL alternative.
This commit routes queries from the `ApkProvider` and `AppProvider` through a
`LoggingQuery` which (in debug builds) times queries, and if they take longer
than a certain threshold, outputs them to logcat. In addition, it will then
ask sqlite to explain its query plan for that same query, and output that to
logcat too.
48ac66b315