Android: Simplify code assist by using KeywordsCompletionProvider

Change-Id: I566e54e8cb539227019fd9cf94113924d1ac9822
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
Reviewed-by: Vikas Pachdha <vikas.pachdha@qt.io>

src/plugins/android/android.pro

@@ -41,7 +41,6 @@ HEADERS += \
     androidsignaloperation.h \
     javaeditor.h \
     javaindenter.h \
-    javacompletionassistprovider.h \
     avddialog.h \
     android_global.h \
     androidbuildapkstep.h \
@@ -86,7 +85,6 @@ SOURCES += \
     androidsignaloperation.cpp \
     javaeditor.cpp \
     javaindenter.cpp \
-    javacompletionassistprovider.cpp \
     avddialog.cpp \
     androidbuildapkstep.cpp \
     androidbuildapkwidget.cpp \