Fix comment about dex compression

Summary:
I introduced a new dex compression method (`raw_subdir`) with corresponding description in D82302583. I just realized I messed up the numbering in the comment:

https://www.internalfb.com/code/fbsource/[a018a61513e801b70447025a195e0f20135f2261]/fbcode/buck2/prelude/android/dex_rules.bzl?lines=37%2C39%2C41%2C46%2C48%2C50

We have 5 compression methods numbered 1, 2, 3, 4, 5 — not 4 compression methods numbered 1, 2, 2, 3, 4. The behavior is unchanged, this merely fixes the comment.

Differential Revision: D82372774

fbshipit-source-id: ff1996b1af371b8f640a00490ea6e00bb68c9d44

Author: Simon Schellaert

android/dex_rules.bzl

@@ -34,7 +34,7 @@ load("@prelude//utils:utils.bzl", "flatten")
 #
 # The primary DEX is always stored in the root directory of the APK as `classes.dex`.
 #
-# We have 4 different ways of storing our secondary DEX files, which are specified via the
+# We have 5 different ways of storing our secondary DEX files, which are specified via the
 # `dex_compression` attribute:
 # 1) `raw` compression. This means that we create `classes2.dex`, `classes3.dex`, ...,
 #    `classesN.dex` and store each of them in the root directory of the APK.
@@ -43,11 +43,11 @@ load("@prelude//utils:utils.bzl", "flatten")
 #    the sense that secondary DEX files are included in the APK without
 #    additional compression. However, those raw DEXes are written to the
 #    secondary dex subdirectory instead of to the root directory of the APK.
-# 2) `jar` compression. For each secondary DEX file, we put a `classes.dex` entry into a
+# 3) `jar` compression. For each secondary DEX file, we put a `classes.dex` entry into a
 #    JAR file, and store it as an asset at `assets/secondary-program-dex-jars/secondary-I.dex.jar`
-# 3) `xz` compression. This is the same as `jar` compression, except that we run `xz` on the
+# 4) `xz` compression. This is the same as `jar` compression, except that we run `xz` on the
 #    JAR file to produce `assets/secondary-program-dex-jars/secondary-I.dex.jar.xz`.
-# 4) `xzs` compression. We do the same as `jar` compression, then concatenate all the jars
+# 5) `xzs` compression. We do the same as `jar` compression, then concatenate all the jars
 #    together and do `xz` compression on the result to produce a single
 #    `assets/secondary-program-dex-jars/secondary.dex.jar.xzs`.
 #