Wrong logic in computeLatitudePrecision

`computeLatitudePrecision` uses a wrong logic:

https://github.com/google/open-location-code/blob/bb54a578c4e2d5af10d27e58dd75860cc8f485d5/java/src/main/java/com/google/openlocationcode/OpenLocationCode.java#L683

Instead, it should compare

```
codeLength <= PAIR_CODE_LENGTH
```

The two constants have different semantics, but the same value (namely 10). So this issue is about code cleanness, not about a wrong run-time behavior.

When fixed, `CODE_PRECISION_NORMAL` would just determine the default precision for the two-parameter `encode`. It might then be increased to 11 to match the OLC precision shown by Google Maps for pins, which is about the GPS accuracy in phones.