Please Upgrade minimum SDK to at least 19

[haole91]

Manifest merger failed : uses-sdk:minSdkVersion 16 cannot be smaller than version 19 declared in library [com.github.mhiew:android-pdf-viewer:3.2.0-beta.3] transformed/jetified-android-pdf-viewer-3.2.0-beta.3/AndroidManifest.xml as the library might be using APIs not available in 16
Suggestion: use a compatible library with a minSdk of at most 16,
or increase this project's minSdk version to at least 19,
or use tools:overrideLibrary="com.github.barteksc.pdfviewer" to force usage (may lead to runtime failures)