Flutter app paused for about 30 seconds to 1 minute during hot reload in IntelliJ or Android Studio

I'm using IntelliJ 2019.1.3 on Ubuntu 19.04. When I make a change then hot reload activates and the IntelliJ Console output shows "The application is paused." After a while it may be responsive again, or freeze long enough that I give up. VSCode hot reloads fine, but I'd prefer to use IntelliJ.

How can I troubleshoot this?

(I also have an SO at https://stackoverflow.com/questions/56992290/flutter-app-paused-for-about-30-seconds-to-1-minute-during-hot-reload-in-intelli)

## Version info
```
==> flutter doctor -v
[✓] Flutter (Channel stable, v1.7.8+hotfix.3, on Linux, locale en_US.UTF-8)
• Flutter version 1.7.8+hotfix.3 at /home/jibbers42/flutter
• Framework revision b712a172f9 (2 days ago), 2019-07-09 13:14:38 -0700
• Engine revision 54ad777fd2
• Dart version 2.4.0

[✓] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
• Android SDK at /home/jibbers42/bin/android-sdk/
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-28, build-tools 28.0.3
• ANDROID_HOME = /home/jibbers42/bin/android-sdk
• ANDROID_SDK_ROOT = /home/jibbers42/bin/android-sdk
• Java binary at:
/home/jibbers42/.local/share/JetBrains/Toolbox/apps/AndroidStudio/ch-0/183.5522156/jre/bin/jav
a
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1343-b16-5323222)
• All Android licenses accepted.

[✓] Android Studio (version 3.4)
• Android Studio at
/home/jibbers42/.local/share/JetBrains/Toolbox/apps/AndroidStudio/ch-0/183.5522156
• Flutter plugin version 35.3.1
• Dart plugin version 183.6270
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1343-b16-5323222)

[✓] IntelliJ IDEA Community Edition (version 2019.1)
• IntelliJ at /home/jibbers42/.local/share/JetBrains/Toolbox/apps/IDEA-C/ch-0/191.7479.19
• Flutter plugin version 37.0.3
• Dart plugin version 191.7830

[✓] VS Code (version 1.36.1)
• VS Code at /usr/share/code
• Flutter extension version 3.2.0

[✓] Connected device (1 available)
• Pixel 3 XL • 89HY071WP • android-arm64 • Android 9 (API 28)

• No issues found!

```