Name [-1,1] the "nominal" range of float samples

Float values are allowed to be > 0dbfs,
it is just not nominal as it will might
distort the signal when played without
attenuation.

This is also consistent with
[AudioTrack.write(FloatBuffer)](https://developer.android.com/reference/android/media/AudioTrack#write(float[],%20int,%20int,%20int)) that explicitly
allows it up to 3dbfs.

PiperOrigin-RevId: 321345077

RELEASENOTES.md

@@ -2,6 +2,8 @@
 
 ### 2.11.8 (2020-08-25) ###
 
+*   Fix distorted playback of floating point audio when samples exceed the
+    `[-1, 1]` nominal range.
 *   MP4: Add support for `piff` and `isml` brands
     ([#7584](https://github.com/google/ExoPlayer/issues/7584)).
 *   FMP4: Fix `saiz` and `senc` sample count checks, resolving a "length

library/core/src/main/java/com/google/android/exoplayer2/audio/ResamplingAudioProcessor.java

@@ -116,7 +116,7 @@ import java.nio.ByteBuffer;
         // 32 bit floating point -> 16 bit resampling. Floating point values are in the range
         // [-1.0, 1.0], so need to be scaled by Short.MAX_VALUE.
         for (int i = position; i < limit; i += 4) {
-          // Clamp to avoid integer overflow if the floating point values exceed their allowed range
+          // Clamp to avoid integer overflow if the floating point values exceed their nominal range
           // [Internal ref: b/161204847].
           float floatValue =
               Util.constrainValue(inputBuffer.getFloat(i), /* min= */ -1, /* max= */ 1);