Draft: Removes keep rules and adds optimized resource shrinking

[AjeshRPai]

This PR fixes #165 by

1. Removes redundant keep rules
2. Adds optimized resource shrinking to the codebase

[gemini-code-assist]

Summary of Changes

Hello @AjeshRPai, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request focuses on optimizing the application's build size and performance by refining ProGuard/R8 configurations. It streamlines the build process by eliminating unnecessary code retention rules and activating advanced resource shrinking capabilities, leading to a more compact and efficient final application package.

Highlights

• Redundant Keep Rules Removed: Several -keep rules in proguard-rules.pro files for various libraries (Firebase, Apache, OkHttp, BouncyCastle, etc.) have been removed, indicating that they are no longer necessary or are handled automatically by R8.
• Optimized Resource Shrinking Enabled: The android.r8.optimizedResourceShrinking=true flag has been added to gradle.properties, enabling more efficient resource shrinking during the build process.
• Kotlin Intrinsics Optimization: New ProGuard rules have been added to assume no side effects for specific methods within kotlin.jvm.internal.Intrinsics, which can lead to further code optimization by R8.

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Changelog

• app/proguard-rules.pro
  • Removed -keep rules for Firebase, Apache, Jackson, Servlet, IETF JGSS, and OkHttp classes.
  • Added -repackageclasses directive.
  • Added -assumenosideeffects rules for Kotlin Intrinsics methods to allow for more aggressive optimization.
• gradle.properties
  • Removed android.disableMinifyLocalDependenciesForLibraries=true.
  • Added android.r8.optimizedResourceShrinking=true to enable optimized resource shrinking.
• watchface/proguard-rules.pro
  • Removed -dontwarn javax.imageio.**.
  • Removed numerous -keep rules for PackPackage, BouncyCastle, APK Signer, Apache Xerces, and various Java XML (JAXP, DOM, SAX) interfaces and classes.

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[gemini-code-assist]

Code Review

This pull request aims to reduce the application size by removing redundant ProGuard keep rules and enabling optimized resource shrinking. The changes include enabling android.r8.optimizedResourceShrinking, adding R8 optimizations for Kotlin intrinsics, and removing several broad keep rules. While these changes are beneficial for optimization, I've raised a concern about the aggressive removal of keep rules in watchface/proguard-rules.pro. Specifically, removing rules for libraries like BouncyCastle and APK Signer, which are known to use reflection, poses a significant risk of runtime crashes. It's crucial to verify that these rules are genuinely redundant before merging.

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watchface/proguard-rules.pro (11-34)

Removing these -keep rules is a high-risk change. Libraries like BouncyCastle, APK Signer, and various XML parsers are often used via reflection, and removing their -keep rules can lead to ClassNotFoundException or other reflection-related crashes at runtime. The comments in the original file for BouncyCastle even explicitly state this. While the goal of removing redundant rules is good, it's critical to ensure these are truly redundant (e.g., because the libraries now ship with their own consumer ProGuard rules). Otherwise, these rules should be restored to prevent potential runtime failures.