Fix library order in class loader context to agree with PackageManager.

PackageManager adds compatibility libraries for different SDK versions
in descending order, and Soong should do the same.

Bug: 132357300

Test: lunch aosp_cf_x86_phone-userdebug && m \
  && launch_cvd \
  && adb wait-for-device \
  && adb logcat | grep -E 'ClassLoaderContext [a-z ]+ mismatch'

  [no messages "ClassLoaderContext classpath element mismatch"]

Change-Id: Ib1d981808ae4022b2c6e73f407a003e8b8e9c7d6
diff --git a/dexpreopt/class_loader_context.go b/dexpreopt/class_loader_context.go
index 874edca..ab789aa 100644
--- a/dexpreopt/class_loader_context.go
+++ b/dexpreopt/class_loader_context.go
@@ -16,6 +16,7 @@
 
 import (
 	"fmt"
+	"sort"
 	"strconv"
 	"strings"
 
@@ -238,8 +239,8 @@
 	AndroidTestMock,
 }
 var CompatUsesLibs29 = []string{
-	AndroidHidlBase,
 	AndroidHidlManager,
+	AndroidHidlBase,
 }
 var OptionalCompatUsesLibs = append(android.CopyOf(OptionalCompatUsesLibs28), OptionalCompatUsesLibs30...)
 var CompatUsesLibs = android.CopyOf(CompatUsesLibs29)
@@ -462,7 +463,26 @@
 // Perform a depth-first preorder traversal of the class loader context tree for each SDK version.
 // Return the resulting string and a slice of on-host build paths to all library dependencies.
 func ComputeClassLoaderContext(clcMap ClassLoaderContextMap) (clcStr string, paths android.Paths) {
-	for _, sdkVer := range android.SortedIntKeys(clcMap) { // determinisitc traversal order
+	// CLC for different SDK versions should come in specific order that agrees with PackageManager.
+	// Since PackageManager processes SDK versions in ascending order and prepends compatibility
+	// libraries at the front, the required order is descending, except for AnySdkVersion that has
+	// numerically the largest order, but must be the last one. Example of correct order: [30, 29,
+	// 28, AnySdkVersion]. There are Soong tests to ensure that someone doesn't change this by
+	// accident, but there is no way to guard against changes in the PackageManager, except for
+	// grepping logcat on the first boot for absence of the following messages:
+	//
+	//   `logcat | grep -E 'ClassLoaderContext [a-z ]+ mismatch`
+	//
+	versions := make([]int, 0, len(clcMap))
+	for ver, _ := range clcMap {
+		if ver != AnySdkVersion {
+			versions = append(versions, ver)
+		}
+	}
+	sort.Sort(sort.Reverse(sort.IntSlice(versions))) // descending order
+	versions = append(versions, AnySdkVersion)
+
+	for _, sdkVer := range versions {
 		sdkVerStr := fmt.Sprintf("%d", sdkVer)
 		if sdkVer == AnySdkVersion {
 			sdkVerStr = "any" // a special keyword that means any SDK version