Embarcadero has made available a new tool for Delphi XE7 developers that helps interfacing with Android Java classes by translating Java APIs to Object Pascal. The download is available here (for registered users):

cc.embarcadero.com/item/30007

How does it work? You can find a good documentation of the tool itself at  docwiki.embarcadero.com/RADStudio/XE7/en/Java2OP.exe,_the_Native_Bridge_File_Generator_for_Android while the read me is available also here www.fmxexpress.com/create-android-java-jar-interface-files-for-delphi-xe7-firemonkey-with-java2op/.

Notice that this is an additional step along with the ability to add an external Java Library to a project and customize alsses.dex, as explained at docwiki.embarcadero.com/RADStudio/XE7/en/Using_a_Custom_Set_of_Java_Libraries_In_Your_RAD_Studio_Android_Apps