Avoid showing stack trace without QTI telephony extension

Author: maxwen <max.weninger@gmail.com>
Date:   Tue Nov 28 17:25:07 2017 +0100

    telephony: dont scare AOSP people

    for AOSP its full ok to not have QtiTelephonyComponentFactory
    so dont scare them with a stack trace but a nice message only

    Change-Id: I6644c4df91f1fbb775c368c62ef1ad90e1874cf7

Author: Alexander Diewald <Diewi@diewald-net.com>
Date:   Tue Jan 16 20:51:31 2018 +0100

    telephony: Construct TelephonyComponentFactory correctly wo qti jar.

    * In the absence of the file "/system/frameworks/qti-telephony-common.jar",
      the default TelephonyComponentFactory shall be instantiated.
      This fails in the current version, since the ClassLoader already
      produces an exception in the absence of the jar. Hence, place
      the ClassLoader construction in the try statement such that
      a TelephonyComponentFactory is constructed for the singleton.
    * No stack trace is shown when the jar is abscent, but an
      informative message as intended before.

    Change-Id: I3b7970ac3f58483d9a044a4252775bf7d32ac217
    Signed-off-by: Alexander Diewald <Diewi@diewald-net.com>

Change-Id: Ib1541a1ecb4b85abf097861707e7315be86b4f18