Re-apply "android: Don't strip debug info out of the AAR"

A revised version of the earlier 23192280:
- Uses --build-id for all archs, not just aarch64
- Also raises Gradle's memory limits

java/android/build.gradle

@@ -54,6 +54,8 @@ android {
             pickFirst 'lib/*/libsignal_jni.so'
             pickFirst 'lib/*/libsignal_jni_testing.so'
         }
+        // Defer stripping to the Android app project.
+        doNotStrip '**/*.so'
     }
 
     publishing {

java/gradle.properties

@@ -1,4 +1,5 @@
 android.enableAdditionalTestOutput=true
 android.useAndroidX=true
 # Don't rely on the HTML output; that's not useful in CI.
-org.gradle.dependency.verification.console=verbose
+org.gradle.dependency.verification.console=verbose
+org.gradle.jvmargs=-Xmx4g -Xms256m -XX:MaxMetaspaceSize=1g

rust/bridge/jni/build.rs

@@ -6,12 +6,15 @@
 use std::env;
 
 fn main() {
-    if env::var("CARGO_CFG_TARGET_ARCH").expect("set by Cargo") == "aarch64"
-        && env::var("CARGO_CFG_TARGET_OS").expect("set by Cargo") == "android"
-    {
-        // HACK: Force libdl to be linked.
-        // Something about the Docker-based build results in it getting skipped;
-        // if we figure out what, we can remove this.
-        println!("cargo:rustc-cdylib-link-arg=-Wl,--no-as-needed,-ldl,--as-needed");
+    if env::var("CARGO_CFG_TARGET_OS").expect("set by Cargo") == "android" {
+        // --build-id ensures that Android Studio's LLDB can map stripped binaries back to their debug info
+        println!("cargo:rustc-cdylib-link-arg=-Wl,--build-id");
+
+        if env::var("CARGO_CFG_TARGET_ARCH").expect("set by Cargo") == "aarch64" {
+            // HACK: Force libdl to be linked.
+            // Something about the Docker-based build results in it getting skipped;
+            // if we figure out what, we can remove this.
+            println!("cargo:rustc-cdylib-link-arg=-Wl,--no-as-needed,-ldl,--as-needed");
+        }
     }
 }