Select count change (already done for ios)

Interestingly, there is not much of a gain on Android.

It's not due to the sqlcipher change (I ran the new load tests on master and the running times were about the same).

So maybe, there is some query optimization happening on the Android side that is not happening on the iOS side?

I rewrote SmartStoreLoadTest.java to do exactly what we do in SFSmartStoreLoadTestSuite.js (interesting to measure Cordova's overhead - which is quite significant in the load tests).

Finally Android is so much slower than iOS that I lowered the number of entries/batches etc we are doing in the load tests so that the tests don't take to too long to run (see https://github.com/forcedotcom/SalesforceMobileSDK-Shared/commit/dc74828d24398349a3f9bdaf473a246fbe763150).