Create "AudioInputAndroid" example.

We can't use the same example for both desktop and Android because we need to
request the RECORD_AUDIO permission on Android and the API for doing this does
not exist on the desktop.

examples/IO/AudioInputAndroid/AndroidManifest.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+          package=""
+          android:versionCode="1"
+          android:versionName="1.0">              
+    <uses-sdk android:minSdkVersion="17" android:targetSdkVersion="28" />
+    <uses-permission android:name="android.permission.RECORD_AUDIO" />
+    <application android:label=""
+                 android:icon="@drawable/icon">
+        <activity android:name=".MainActivity"
+                  android:theme="@style/Theme.AppCompat.Light.NoActionBar.FullScreen">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity> 
+    </application>
+</manifest>

examples/IO/AudioInputAndroid/AudioInputAndroid.pde

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+/**
+ * Grab audio from the microphone input and draw a circle whose size
+ * is determined by how loud the audio input is.
+ * 
+ * The only difference between this example and AudioInput is that
+ * Android requires requesting the permission RECORD_AUDIO.
+ */
+
+import processing.sound.*;
+
+AudioIn input;
+Amplitude loudness;
+
+void setup() {
+  size(640, 360);
+  background(255);
+
+  if (hasPermission("android.permission.RECORD_AUDIO")) {
+    initialize(true);
+  } else {
+    requestPermission("android.permission.RECORD_AUDIO", "initialize");
+  }
+}
+
+void initialize(boolean granted) {
+  if (!granted) {
+    return;
+  }
+
+  // Create an Audio input and grab the 1st channel
+  input = new AudioIn(this, 0);
+
+  // Begin capturing the audio input
+  input.start();
+  // start() activates audio capture so that you can use it as
+  // the input to live sound analysis, but it does NOT cause the
+  // captured audio to be played back to you. if you also want the
+  // microphone input to be played back to you, call
+  //    input.play();
+  // instead (be careful with your speaker volume, you might produce
+  // painful audio feedback. best to first try it out wearing headphones!)
+
+  // Create a new Amplitude analyzer
+  loudness = new Amplitude(this);
+
+  // Patch the input to the volume analyzer
+  loudness.input(input);
+}
+
+void draw() {
+  if (input == null) {
+    // Wait for user to give permission
+    return;
+  }
+
+  // Adjust the volume of the audio input based on mouse position
+  float inputLevel = map(mouseY, 0, height, 1.0, 0.0);
+  input.amp(inputLevel);
+
+  // loudness.analyze() return a value between 0 and 1. To adjust
+  // the scaling and mapping of an ellipse we scale from 0 to 0.5
+  float volume = loudness.analyze();
+  int size = int(map(volume, 0, 0.5, 1, 350));
+
+  background(125, 255, 125);
+  noStroke();
+  fill(255, 0, 150);
+  // We draw a circle whose size is coupled to the audio analysis
+  ellipse(width/2, height/2, size, size);
+}