don't throw unhandled Exception if audio message is unplayable
don't throw unhandled Exception if audio message is unplayable

When it is not possible to find the audio message to play, don't just crash
on a pointless, unhandled Exception. Instead put the error in a Toast, for
now.  I'm sure this can be presented to the user much better, but this at
least stops the crashes.

closes #4172 https://dev.guardianproject.info/issues/4172

here's the stacktrace:

java.lang.RuntimeException: Unable to start activity ComponentInfo{info.guardianproject.otr.app.im/info.guardianproject.otr.app.im.ui.AudioPlayerActivity}: java.lang.RuntimeException: java.io.IOException: File not found /2/download/Voice+102.3ga
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.RuntimeException: java.io.IOException: File not found /2/download/Voice+102.3ga
at info.guardianproject.otr.app.im.ui.AudioPlayerActivity.play(AudioPlayerActivity.java:96)
at info.guardianproject.otr.app.im.ui.AudioPlayerActivity.onCreate(AudioPlayerActivity.java:53)
at android.app.Activity.performCreate(Activity.java:5933)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
... 10 more
Caused by: java.io.IOException: File not found /2/download/Voice+102.3ga
at info.guardianproject.util.HttpMediaStreamer.create(HttpMediaStreamer.java:50)
at info.guardianproject.util.HttpMediaStreamer.<init>(HttpMediaStreamer.java:30)
at info.guardianproject.otr.app.im.ui.AudioPlayerActivity.initPlayer(AudioPlayerActivity.java:140)
at info.guardianproject.otr.app.im.ui.AudioPlayerActivity.play(AudioPlayerActivity.java:93)
... 14 more

eighthave/ChatSecureAndroid,n8fr8/ChatSecureAndroid,prembasumatary/ChatSecureAndroid,prembasumatary/ChatSecureAndroid,bonashen/ChatSecureAndroid,n8fr8/ChatSecureAndroid,guardianproject/ChatSecureAndroid,Heart2009/ChatSecureAndroid,kden/ChatSecureAndroid,n8fr8/AwesomeApp,n8fr8/ChatSecureAndroid,anvayarai/my-ChatSecure,Heart2009/ChatSecureAndroid,h2ri/ChatSecureAndroid,guardianproject/ChatSecureAndroid,bonashen/ChatSecureAndroid,anvayarai/my-ChatSecure,n8fr8/AwesomeApp,n8fr8/AwesomeApp,Heart2009/ChatSecureAndroid,joskarthic/chatsecure,kden/ChatSecureAndroid,h2ri/ChatSecureAndroid,prembasumatary/ChatSecureAndroid,joskarthic/chatsecure,eighthave/ChatSecureAndroid,h2ri/ChatSecureAndroid,guardianproject/ChatSecureAndroid,kden/ChatSecureAndroid,eighthave/ChatSecureAndroid,anvayarai/my-ChatSecure,bonashen/ChatSecureAndroid,joskarthic/chatsecure