Replace ApiStrToNum uses with ApiLevel.

Test: treehugger
Bug: http://b/154667674
Change-Id: I2954bb21c1cfdeb305f25cfb6c8711c930f6ed50
diff --git a/apex/builder.go b/apex/builder.go
index c5680ad..a3c4d5c 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -21,7 +21,6 @@
 	"path/filepath"
 	"runtime"
 	"sort"
-	"strconv"
 	"strings"
 
 	"android/soong/android"
@@ -214,7 +213,8 @@
 		},
 	})
 
-	if a.minSdkVersion(ctx) == android.SdkVersion_Android10 {
+	minSdkVersion := a.minSdkVersion(ctx)
+	if minSdkVersion.EqualTo(android.SdkVersion_Android10) {
 		// b/143654022 Q apexd can't understand newly added keys in apex_manifest.json
 		// prepare stripped-down version so that APEX modules built from R+ can be installed to Q
 		a.manifestJsonOut = android.PathForModuleOut(ctx, "apex_manifest.json")
@@ -426,7 +426,8 @@
 	var emitCommands []string
 	imageContentFile := android.PathForModuleOut(ctx, "content.txt")
 	emitCommands = append(emitCommands, "echo ./apex_manifest.pb >> "+imageContentFile.String())
-	if a.minSdkVersion(ctx) == android.SdkVersion_Android10 {
+	minSdkVersion := a.minSdkVersion(ctx)
+	if minSdkVersion.EqualTo(android.SdkVersion_Android10) {
 		emitCommands = append(emitCommands, "echo ./apex_manifest.json >> "+imageContentFile.String())
 	}
 	for _, fi := range a.filesInfo {
@@ -536,8 +537,9 @@
 		// TODO(b/157078772): propagate min_sdk_version to apexer.
 		minSdkVersion := ctx.Config().DefaultAppTargetSdk()
 
-		if a.minSdkVersion(ctx) == android.SdkVersion_Android10 {
-			minSdkVersion = strconv.Itoa(a.minSdkVersion(ctx))
+		moduleMinSdkVersion := a.minSdkVersion(ctx)
+		if moduleMinSdkVersion.EqualTo(android.SdkVersion_Android10) {
+			minSdkVersion = moduleMinSdkVersion.String()
 		}
 
 		if java.UseApiFingerprint(ctx) {
@@ -566,7 +568,7 @@
 			ctx.PropertyErrorf("test_only_no_hashtree", "not available")
 			return
 		}
-		if a.minSdkVersion(ctx) > android.SdkVersion_Android10 || a.testOnlyShouldSkipHashtreeGeneration() {
+		if moduleMinSdkVersion.GreaterThan(android.SdkVersion_Android10) || a.testOnlyShouldSkipHashtreeGeneration() {
 			// Apexes which are supposed to be installed in builtin dirs(/system, etc)
 			// don't need hashtree for activation. Therefore, by removing hashtree from
 			// apex bundle (filesystem image in it, to be specific), we can save storage.
@@ -583,7 +585,7 @@
 			optFlags = append(optFlags, "--do_not_check_keyname")
 		}
 
-		if a.minSdkVersion(ctx) == android.SdkVersion_Android10 {
+		if moduleMinSdkVersion == android.SdkVersion_Android10 {
 			implicitInputs = append(implicitInputs, a.manifestJsonOut)
 			optFlags = append(optFlags, "--manifest_json "+a.manifestJsonOut.String())
 		}