proguard-android.txt breaks builds on AGP 9 — switch to proguard-android-optimize.txt

**Describe the bug**
Using `proguard-android.txt` in `android/build.gradle` breaks builds on AGP 9

**To Reproduce**
Upgrade project to Android Plugin Gradle 9 - in `android/build.grade`:
```
classpath 'com.android.tools.build:gradle:9.1.1'
```
Then build Android project.

**Expected behavior**
Expect project to build and run normally.

**Actual behavior**
```
A problem occurred evaluating project ':app'.
> `getDefaultProguardFile('proguard-android.txt')` is no longer supported since it includes `-dontoptimize`, which prevents R8 from performing many optimizations. Instead use `getDefaultProguardFile('proguard-android-optimize.txt)`, and if needed, temporarily use `-dontoptimize` in a custom keep rule file while fixing breakages.
```

**Additional context**
[See Android Docs](https://developer.android.com/topic/performance/app-optimization/library-optimization#optimize-aar)

Fix in `android/build.gradle`
```
- proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+ proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
```