Fix PrecisionRectangle#getBottom inconsistency

[akoch-yatta]

The y value of PrecisionRectangle#getBottom can return a different y value to PrecisionRectangle#getBottomLeft and PrecisionRectangle#getBottomRight because the first uses the int values the later two use precision values. This commit adapt PrecisionRectangle#getBottom to use the precision values as well.

Similar applies at least to getLeft (only regarding the center y coord) and getRight, as both are not overwritten in PrecisionRectangle, but I did not touch them for this PR.