Add getPdfDocument method to PdfFile and update PDFView to use it for…

… page count

Fix load complete callback to use pdfiumCore for accurate page count

Remove redundant null checks for pdfFile in various methods to stream…

…line code

Add null checks for pdfFile in various methods to prevent potential c…

…rashes

Bump version name to 3.2.0-beta.2 in build.gradle

Merge pull request TalbotGooday#5 from muthuraj57/master

Provided option to perform page snap without animation