Add Android sample (#277)

* Add Android sample

* Use main project C files

* Stop existing playback before starting new playback

* Make text scrollable

* Stop playback when starting to record

* Remove extra var

examples/whisper.android/app/src/androidTest/java/com/whispercppdemo/ExampleInstrumentedTest.kt

@@ -0,0 +1,24 @@
+package com.whispercppdemo
+
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.ext.junit.runners.AndroidJUnit4
+
+import org.junit.Test
+import org.junit.runner.RunWith
+
+import org.junit.Assert.*
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class ExampleInstrumentedTest {
+    @Test
+    fun useAppContext() {
+        // Context of the app under test.
+        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+        assertEquals("com.whispercppdemo", appContext.packageName)
+    }
+}