OboeTester needs waveform and correlation plots

[philburk]

That will help us analyze problems more easily without having to export the WAV file.

[philburk]

Waveforms could be displayed in a separate Activity from the Latency test because the screen is small.

[philburk]

Waveforms to display should include:

• output signal
• output signal after peak follower, high pass filter, etc.
• recorded signal
• recorded signal after peak follower, high pass filter, etc.
• correlation array

[philburk]

Waveform display class is at: https://github.com/google/oboe/blob/main/apps/OboeTester/app/src/main/java/com/mobileer/oboetester/WaveformView.java

Analyzer with various signals and an AudioRecording class is at: https://github.com/google/oboe/blob/main/apps/OboeTester/app/src/main/cpp/analyzer/LatencyAnalyzer.h